diff --git a/README.md b/README.md
index 42cec4b..265510d 100755
--- a/README.md
+++ b/README.md
@@ -7,17 +7,74 @@ Service URL(부산소프트웨어마이스터고등학교) : [https://obtuse.kr/
 -   ATPT_OFCDC_SC_CODE = 시도교육청코드
 -   SD_SCHUL_CODE = 표준행정코드
 
+## 프로젝트 구조
+
+이 프로젝트는 모듈화된 구조로 각 컴포넌트의 역할과 책임이 명확히 분리되어 있습니다:
+
+```
+├── main.py              # 애플리케이션 진입점
+├── config/              # 설정 관리
+│   ├── __init__.py
+│   └── settings.py      # 설정 로딩 및 관리
+├── models/              # 데이터 모델
+│   ├── __init__.py
+│   ├── entities.py      # 비즈니스 엔티티
+│   └── schemas.py       # API 요청/응답 스키마
+├── services/            # 비즈니스 로직 서비스
+│   ├── __init__.py
+│   ├── neis_service.py  # NEIS API 상호작용
+│   ├── ics_service.py   # ICS 파일 변환
+│   ├── school_service.py # 학교 데이터 관리
+│   └── cache_service.py # 캐싱 관리
+├── utils/               # 유틸리티 함수
+│   ├── __init__.py
+│   ├── date_utils.py    # 날짜 처리
+│   └── file_utils.py    # 파일 시스템 작업
+├── api/                 # API 라우트
+│   ├── __init__.py
+│   └── routes.py        # FastAPI 엔드포인트
+├── templates/           # HTML 템플릿
+├── data/               # 학교 데이터 파일
+└── server.py           # 레거시 단일 파일 (호환성을 위해 유지)
+```
+
+## 실행 방법
+
+### 요구사항
+- Python 3.8 이상
+- 필요한 패키지들 (requirements.txt 참고)
+
+### 설정
+1. `config.json` 파일을 생성하고 NEIS API 키를 설정합니다:
+```json
+{
+  "neisKey": "your-neis-api-key-here",
+  "cache_day": 7
+}
+```
+
+### 서버 실행
+```bash
+# 의존성 설치
+pip install -r requirements.txt
+
+# 서버 실행 (모듈화된 버전)
+uvicorn main:app --host 0.0.0.0 --port 8000
+
+# 또는 레거시 버전
+uvicorn server:app --host 0.0.0.0 --port 8000
+```
+
+### API 사용법
+- 웹 인터페이스: `http://localhost:8000`
+- 학교 검색: `POST /search`
+- ICS 파일 다운로드: `GET /school?ATPT_OFCDC_SC_CODE={코드}&SD_SCHUL_CODE={코드}`
+
 ## 시도교육청코드 / 행정표준코드 조회방법
 
 -   [https://open.neis.go.kr/portal/data/service/selectServicePage.do?page=1&rows=10&sortColumn=&sortDirection=&infId=OPEN17020190531110010104913&infSeq=1](https://open.neis.go.kr/portal/data/service/selectServicePage.do?page=1&rows=10&sortColumn=&sortDirection=&infId=OPEN17020190531110010104913&infSeq=1)에 접속해서 시도교육청코드와 행정표준코드를 조회할 수 있습니다.
 -   [![image.png](image.png)](image.png)
 
-## 참고
-
--   simple.js : 나이스 api 호출하지 않음
--   index.js : 나이스 api 호출
--   server.js : api 서버로 작동하는 코드
-
 ### 작동 테스트
 - 애플 캘린더 : ✅
 - 구글 캘린더 : ✅
@@ -28,6 +85,16 @@ Service URL(부산소프트웨어마이스터고등학교) : [https://obtuse.kr/
 (다른 캘린더에서도 작동하지 않는다면 Issue 등록해주시면 감사하겠습니다.)
 (해결해서 Pull Requst 보내주시면 더 감사하겠습니다.)
 
+## 레거시 파일 참고
+
+이 프로젝트는 기존 단일 파일 구조에서 모듈화된 구조로 리팩토링되었습니다:
+
+### Python 버전
+-   `server.py` : 기존 단일 파일 (147줄, 호환성을 위해 유지)
+-   `main.py` + 모듈들 : 새로운 모듈화 구조 (354줄, 16개 파일)
+
+### JavaScript 레거시 (.legacy 폴더)
+
 ## simple.js 사용법
 
 -   나이스 학사일정 api를 이용해 학사일정을 json형식으로 가져옵니다.
diff --git a/api/__init__.py b/api/__init__.py
new file mode 100644
index 0000000..5122e86
--- /dev/null
+++ b/api/__init__.py
@@ -0,0 +1,4 @@
+"""API module."""
+from .routes import get_school, index, school_search
+
+__all__ = ["get_school", "index", "school_search"]
\ No newline at end of file
diff --git a/api/routes.py b/api/routes.py
new file mode 100644
index 0000000..b337ff4
--- /dev/null
+++ b/api/routes.py
@@ -0,0 +1,45 @@
+"""API routes for the application."""
+from fastapi import Request, HTTPException
+from fastapi.responses import FileResponse, JSONResponse
+from fastapi.templating import Jinja2Templates
+
+from models import SchoolSearch
+from services import neis_service, ics_service, school_service, cache_service
+
+
+templates = Jinja2Templates(directory="templates")
+
+
+async def get_school(ATPT_OFCDC_SC_CODE: str, SD_SCHUL_CODE: int):
+    """Get school schedule as ICS file."""
+    if ATPT_OFCDC_SC_CODE is None or SD_SCHUL_CODE is None:
+        return {"message": "시도교육청 코드와 학교 코드를 입력해주세요. 예) /school?ATPT_OFCDC_SC_CODE=C10&SD_SCHUL_CODE=7150658"}
+
+    # Check cache first
+    cached_content = cache_service.get_cached_content(ATPT_OFCDC_SC_CODE, SD_SCHUL_CODE)
+    if cached_content:
+        file_path = cache_service.get_cache_path(ATPT_OFCDC_SC_CODE, SD_SCHUL_CODE)
+        return FileResponse(file_path, media_type='text/calendar', filename='school_schedule.ics')
+
+    # Fetch from NEIS API and convert to ICS
+    json_data = await neis_service.get_school_schedule(ATPT_OFCDC_SC_CODE, SD_SCHUL_CODE)
+    ics_data = ics_service.convert_to_ics(json_data)
+    
+    # Save to cache
+    file_path = cache_service.save_to_cache(ATPT_OFCDC_SC_CODE, SD_SCHUL_CODE, ics_data)
+    
+    return FileResponse(file_path, media_type='text/calendar', filename='school_schedule.ics')
+
+
+async def index(request: Request):
+    """Render the index page."""
+    return templates.TemplateResponse("index.html", {"request": request})
+
+
+async def school_search(school_search: SchoolSearch):
+    """Search for schools."""
+    result = school_service.search_schools(
+        school_search.ATPT_OFCDC_SC_CODE, 
+        school_search.SCHUL_NM
+    )
+    return JSONResponse(content=result)
\ No newline at end of file
diff --git a/config/__init__.py b/config/__init__.py
new file mode 100644
index 0000000..0b8737a
--- /dev/null
+++ b/config/__init__.py
@@ -0,0 +1,4 @@
+"""Configuration module."""
+from .settings import settings
+
+__all__ = ["settings"]
\ No newline at end of file
diff --git a/config/settings.py b/config/settings.py
new file mode 100644
index 0000000..8879296
--- /dev/null
+++ b/config/settings.py
@@ -0,0 +1,36 @@
+"""Configuration management module."""
+import json
+import os
+from typing import Dict, Any
+
+
+class Settings:
+    """Application settings management."""
+    
+    def __init__(self, config_path: str = "config.json"):
+        self.config_path = config_path
+        self._config = self._load_config()
+    
+    def _load_config(self) -> Dict[str, Any]:
+        """Load configuration from JSON file."""
+        try:
+            with open(self.config_path, "r") as f:
+                return json.load(f)
+        except FileNotFoundError:
+            raise FileNotFoundError(f"Configuration file {self.config_path} not found")
+        except json.JSONDecodeError:
+            raise ValueError(f"Invalid JSON in configuration file {self.config_path}")
+    
+    @property
+    def neis_key(self) -> str:
+        """Get NEIS API key."""
+        return self._config.get("neisKey", "")
+    
+    @property
+    def cache_days(self) -> int:
+        """Get cache expiration days."""
+        return self._config.get("cache_day", 7)
+
+
+# Global settings instance
+settings = Settings()
\ No newline at end of file
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..76dae6a
--- /dev/null
+++ b/main.py
@@ -0,0 +1,27 @@
+"""Main application entry point."""
+from fastapi import FastAPI, Request
+
+from api import get_school, index, school_search
+from models import SchoolSearch
+
+
+app = FastAPI()
+
+
+# Register routes
+@app.get("/school")
+async def school_endpoint(ATPT_OFCDC_SC_CODE: str, SD_SCHUL_CODE: int):
+    """Get school schedule endpoint."""
+    return await get_school(ATPT_OFCDC_SC_CODE, SD_SCHUL_CODE)
+
+
+@app.get("/")
+async def index_endpoint(request: Request):
+    """Index page endpoint."""
+    return await index(request)
+
+
+@app.post("/search")
+async def search_endpoint(school_search_data: SchoolSearch):
+    """School search endpoint."""
+    return await school_search(school_search_data)
\ No newline at end of file
diff --git a/models/__init__.py b/models/__init__.py
new file mode 100644
index 0000000..7839eea
--- /dev/null
+++ b/models/__init__.py
@@ -0,0 +1,5 @@
+"""Models module."""
+from .schemas import SchoolSearch
+from .entities import SchoolEvent, SchoolSchedule
+
+__all__ = ["SchoolSearch", "SchoolEvent", "SchoolSchedule"]
\ No newline at end of file
diff --git a/models/entities.py b/models/entities.py
new file mode 100644
index 0000000..8634547
--- /dev/null
+++ b/models/entities.py
@@ -0,0 +1,30 @@
+"""Data entity classes."""
+from typing import Dict, List, Any
+from datetime import datetime
+
+
+class SchoolEvent:
+    """Represents a school event from NEIS API."""
+    
+    def __init__(self, event_data: Dict[str, Any]):
+        self.date = event_data.get('AA_YMD', '')
+        self.event_name = event_data.get('EVENT_NM', '')
+        self.event_content = event_data.get('EVENT_CNTNT', '')
+        self.school_name = event_data.get('SCHUL_NM', '')
+
+
+class SchoolSchedule:
+    """Represents a complete school schedule."""
+    
+    def __init__(self, schedule_data: Dict[str, Any]):
+        self.events: List[SchoolEvent] = []
+        self.school_name = ""
+        
+        if 'SchoolSchedule' in schedule_data:
+            for item in schedule_data['SchoolSchedule']:
+                if 'row' in item:
+                    for event_data in item['row']:
+                        event = SchoolEvent(event_data)
+                        self.events.append(event)
+                        if not self.school_name and event.school_name:
+                            self.school_name = event.school_name
\ No newline at end of file
diff --git a/models/schemas.py b/models/schemas.py
new file mode 100644
index 0000000..bd65476
--- /dev/null
+++ b/models/schemas.py
@@ -0,0 +1,8 @@
+"""Pydantic models for API requests and responses."""
+from pydantic import BaseModel
+
+
+class SchoolSearch(BaseModel):
+    """Model for school search requests."""
+    ATPT_OFCDC_SC_CODE: str
+    SCHUL_NM: str
\ No newline at end of file
diff --git a/services/__init__.py b/services/__init__.py
new file mode 100644
index 0000000..13ce623
--- /dev/null
+++ b/services/__init__.py
@@ -0,0 +1,7 @@
+"""Services module."""
+from .neis_service import neis_service
+from .ics_service import ics_service
+from .school_service import school_service
+from .cache_service import cache_service
+
+__all__ = ["neis_service", "ics_service", "school_service", "cache_service"]
\ No newline at end of file
diff --git a/services/cache_service.py b/services/cache_service.py
new file mode 100644
index 0000000..59e7502
--- /dev/null
+++ b/services/cache_service.py
@@ -0,0 +1,52 @@
+"""Cache service for managing cached ICS files."""
+import os
+import re
+from datetime import datetime, timedelta
+from typing import Optional
+
+from config import settings
+from utils import ensure_directory_existence
+
+
+class CacheService:
+    """Service for managing cached ICS files."""
+    
+    def __init__(self, cache_dir: str = "cache"):
+        self.cache_dir = cache_dir
+    
+    def get_cache_path(self, atpt_ofcdc_sc_code: str, sd_schul_code: int) -> str:
+        """Get the cache file path for given school codes."""
+        return os.path.join(self.cache_dir, atpt_ofcdc_sc_code, f"{sd_schul_code}.ics")
+    
+    def get_cached_content(self, atpt_ofcdc_sc_code: str, sd_schul_code: int) -> Optional[str]:
+        """Get cached ICS content if valid, otherwise return None."""
+        file_path = self.get_cache_path(atpt_ofcdc_sc_code, sd_schul_code)
+        
+        if not os.path.exists(file_path):
+            return None
+        
+        with open(file_path, "r", encoding="utf8") as file:
+            content = file.read()
+            match = re.search(
+                r'X-CREATED-TIME:(\d{4}-\d{2}-\d{2})T\d{2}:\d{2}:\d{2}.\d{3}Z', 
+                content
+            )
+            
+            if match and datetime.now() - datetime.fromisoformat(match.group(1)) < timedelta(days=settings.cache_days):
+                return content
+        
+        return None
+    
+    def save_to_cache(self, atpt_ofcdc_sc_code: str, sd_schul_code: int, content: str) -> str:
+        """Save ICS content to cache and return the file path."""
+        file_path = self.get_cache_path(atpt_ofcdc_sc_code, sd_schul_code)
+        ensure_directory_existence(file_path)
+        
+        with open(file_path, "w", encoding="utf8") as file:
+            file.write(content)
+        
+        return file_path
+
+
+# Global service instance
+cache_service = CacheService()
\ No newline at end of file
diff --git a/services/ics_service.py b/services/ics_service.py
new file mode 100644
index 0000000..7396b47
--- /dev/null
+++ b/services/ics_service.py
@@ -0,0 +1,59 @@
+"""ICS conversion service for converting school data to ICS format."""
+from datetime import datetime
+from typing import Dict, Any
+
+from utils import parse_date, format_date
+from models import SchoolSchedule, SchoolEvent
+
+
+class IcsService:
+    """Service for converting school schedules to ICS format."""
+    
+    def convert_to_ics(self, data: Dict[str, Any]) -> str:
+        """Convert NEIS schedule data to ICS format."""
+        schedule = SchoolSchedule(data)
+        today = datetime.utcnow().strftime('%Y%m%dT%H%M%SZ')
+        
+        ics = f"""BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//obtuse.kr//SchoolScheduleToICS//KO
+CALSCALE:GREGORIAN
+X-WR-CALNAME:{schedule.school_name} 학사일정
+X-WR-TIMEZONE:Asia/Seoul
+BEGIN:VTIMEZONE
+TZID:Asia/Seoul
+TZURL:https://www.tzurl.org/zoneinfo-outlook/Asia/Seoul
+X-LIC-LOCATION:Asia/Seoul
+BEGIN:STANDARD
+DTSTART:19700101T000000
+TZNAME:KST
+TZOFFSETFROM:+0900
+TZOFFSETTO:+0900
+END:STANDARD
+END:VTIMEZONE
+X-CREATED-TIME:{datetime.utcnow().isoformat()}\n"""
+
+        for event in schedule.events:
+            start_date = parse_date(event.date)
+            ics += f"""BEGIN:VEVENT
+DTSTART;VALUE=DATE:{format_date(start_date)}
+TRANSP:OPAQUE
+DTSTAMP:{today}
+X-MICROSOFT-CDO-BUSYSTATUS:BUSY
+CLASS:PUBLIC
+BEGIN:VALARM
+ACTION:DISPLAY
+DESCRIPTION:{event.event_name}
+TRIGGER:-P1D
+END:VALARM
+SUMMARY:{event.event_name}
+DESCRIPTION:{event.event_content}
+LOCATION:{event.school_name}
+END:VEVENT\n"""
+        
+        ics += "END:VCALENDAR"
+        return ics
+
+
+# Global service instance
+ics_service = IcsService()
\ No newline at end of file
diff --git a/services/neis_service.py b/services/neis_service.py
new file mode 100644
index 0000000..5637d7c
--- /dev/null
+++ b/services/neis_service.py
@@ -0,0 +1,33 @@
+"""NEIS API service for fetching school schedule data."""
+import requests
+from datetime import datetime
+from typing import Dict, Any
+from fastapi import HTTPException
+
+from config import settings
+
+
+class NeisService:
+    """Service for interacting with NEIS API."""
+    
+    def __init__(self):
+        self.base_url = "https://open.neis.go.kr/hub/SchoolSchedule"
+    
+    async def get_school_schedule(self, atpt_ofcdc_sc_code: str, sd_schul_code: int) -> Dict[str, Any]:
+        """Fetch school schedule from NEIS API."""
+        url = f"{self.base_url}?KEY={settings.neis_key}&Type=json&ATPT_OFCDC_SC_CODE={atpt_ofcdc_sc_code}&SD_SCHUL_CODE={sd_schul_code}&MLSV_FROM_YMD={datetime.now().year}0101&MLSV_TO_YMD={(datetime.now().year + 1)}0101&pSize=1000"
+        
+        print(url)  # For debugging
+        response = requests.get(url)
+        
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise HTTPException(
+                status_code=response.status_code,
+                detail="Error fetching data from NEIS server"
+            )
+
+
+# Global service instance
+neis_service = NeisService()
\ No newline at end of file
diff --git a/services/school_service.py b/services/school_service.py
new file mode 100644
index 0000000..06f452d
--- /dev/null
+++ b/services/school_service.py
@@ -0,0 +1,31 @@
+"""School data service for managing school information."""
+import pandas as pd
+from typing import List, Dict, Any
+
+
+class SchoolService:
+    """Service for managing school data."""
+    
+    def __init__(self, data_file: str = "data/학교기본정보2024_11_30.csv"):
+        self.data_file = data_file
+        self._school_data = self._load_school_data()
+    
+    def _load_school_data(self) -> pd.DataFrame:
+        """Load school data from CSV file."""
+        with open(self.data_file, "r", encoding='cp949') as f:
+            return pd.read_csv(f)
+    
+    def search_schools(self, atpt_ofcdc_sc_code: str, school_name: str) -> List[Dict[str, Any]]:
+        """Search for schools by education office code and name."""
+        result = self._school_data[
+            (self._school_data['시도교육청코드'] == atpt_ofcdc_sc_code) & (
+                self._school_data['학교명'].str.contains(school_name, na=False) | 
+                self._school_data['영문학교명'].str.contains(school_name, na=False)
+            )
+        ].fillna(value="").to_dict(orient='records')
+        
+        return result
+
+
+# Global service instance
+school_service = SchoolService()
\ No newline at end of file
diff --git a/utils/__init__.py b/utils/__init__.py
new file mode 100644
index 0000000..7f9826e
--- /dev/null
+++ b/utils/__init__.py
@@ -0,0 +1,5 @@
+"""Utilities module."""
+from .date_utils import parse_date, format_date
+from .file_utils import ensure_directory_existence
+
+__all__ = ["parse_date", "format_date", "ensure_directory_existence"]
\ No newline at end of file
diff --git a/utils/date_utils.py b/utils/date_utils.py
new file mode 100644
index 0000000..afc1de6
--- /dev/null
+++ b/utils/date_utils.py
@@ -0,0 +1,15 @@
+"""Date utilities for parsing and formatting dates."""
+from datetime import datetime
+
+
+def parse_date(date_string: str) -> datetime:
+    """Parse NEIS date string (YYYYMMDD) to datetime object."""
+    year = int(date_string[:4])
+    month = int(date_string[4:6])
+    day = int(date_string[6:8])
+    return datetime(year, month, day)
+
+
+def format_date(date: datetime) -> str:
+    """Format datetime object to YYYYMMDD string."""
+    return date.strftime("%Y%m%d")
\ No newline at end of file
diff --git a/utils/file_utils.py b/utils/file_utils.py
new file mode 100644
index 0000000..aa076c4
--- /dev/null
+++ b/utils/file_utils.py
@@ -0,0 +1,9 @@
+"""File system utilities."""
+import os
+
+
+def ensure_directory_existence(file_path: str) -> None:
+    """Ensure the directory for the given file path exists."""
+    dirname = os.path.dirname(file_path)
+    if not os.path.exists(dirname):
+        os.makedirs(dirname)
\ No newline at end of file