diff --git a/apps/server/src/domains/room/RoomHandler.ts b/apps/server/src/domains/room/RoomHandler.ts
index 756cb63..9483894 100644
--- a/apps/server/src/domains/room/RoomHandler.ts
+++ b/apps/server/src/domains/room/RoomHandler.ts
@@ -4,8 +4,10 @@
 import type { roomTypes } from "@repo/shared";
 import { joinRoomUseCase } from "./application/useCases/joinRoomUseCase";
 import { roomDisconnectUseCase } from "./application/useCases/roomDisconnectUseCase";
+import { createEmitToRoom } from "./application/adapters/createEmitToRoom";
 
 export const registerRoomHandlers = (io: Server, socket: Socket, roomManager: RoomManager) => {
+  const emitToRoom = createEmitToRoom(io);
   
   socket.on(protocol.SocketEvents.JOIN_ROOM, (data: roomTypes.JoinRoomPayload) => {
     const { roomId } = data;
@@ -16,14 +18,7 @@
       roomManager,
       socketId: socket.id,
       data,
-      emitToRoom: (targetRoomId, event, payload) => {
-        if (payload === undefined) {
-          io.to(targetRoomId).emit(event);
-          return;
-        }
-
-        io.to(targetRoomId).emit(event, payload);
-      },
+      emitToRoom,
     });
   });
 
@@ -33,16 +28,11 @@
  * 切断時のルームクリーンアップ処理
  */
 export const handleRoomDisconnect = (io: Server, socket: Socket, roomManager: RoomManager) => {
+  const emitToRoom = createEmitToRoom(io);
+
   roomDisconnectUseCase({
     roomManager,
     socketId: socket.id,
-    emitToRoom: (roomId, event, payload) => {
-      if (payload === undefined) {
-        io.to(roomId).emit(event);
-        return;
-      }
-
-      io.to(roomId).emit(event, payload);
-    },
+    emitToRoom,
   });
 };
\ No newline at end of file
diff --git a/apps/server/src/domains/room/RoomManager.ts b/apps/server/src/domains/room/RoomManager.ts
index 48832ec..defaf38 100644
--- a/apps/server/src/domains/room/RoomManager.ts
+++ b/apps/server/src/domains/room/RoomManager.ts
@@ -1,83 +1,32 @@
-import { roomConsts, config } from "@repo/shared";
 import type { roomTypes } from "@repo/shared";
+import { RoomJoinService } from "./application/services/RoomJoinService";
+import { RoomExitService } from "./application/services/RoomExitService";
+import { RoomQueryService } from "./application/services/RoomQueryService";
 
 export class RoomManager {
   private rooms: Map<string, roomTypes.Room> = new Map();
+  private roomJoinService: RoomJoinService;
+  private roomExitService: RoomExitService;
+  private roomQueryService: RoomQueryService;
+
+  constructor() {
+    this.roomJoinService = new RoomJoinService(this.rooms);
+    this.roomExitService = new RoomExitService(this.rooms);
+    this.roomQueryService = new RoomQueryService(this.rooms);
+  }
 
   // ルームにプレイヤーを追加（なければ作成）
   public addPlayerToRoom(roomId: string, socketId: string, playerName: string): roomTypes.Room {
-    let room = this.rooms.get(roomId);
-    if (!room) {
-      room = {
-        roomId: roomId,
-        ownerId: socketId,
-        players: [],
-        status: roomConsts.RoomPhase.WAITING,
-        maxPlayers: config.GAME_CONFIG.MAX_PLAYERS_PER_ROOM
-      };
-      this.rooms.set(roomId, room);
-      console.log("[RoomManager] created room", { roomId, ownerId: socketId });
-    }
-
-    const newPlayer: roomTypes.RoomMember = {
-      id: socketId,
-      name: playerName,
-      isOwner: room.ownerId === socketId,
-      isReady: false
-    };
-    room.players.push(newPlayer);
-    console.log("[RoomManager] player joined", {
-      roomId,
-      socketId,
-      playerName,
-      totalPlayers: room.players.length
-    });
-
-    return room;
+    return this.roomJoinService.addPlayerToRoom(roomId, socketId, playerName);
   }
 
   // プレイヤーをルームから削除し、更新があったルームの配列を返す
   public removePlayer(socketId: string): roomTypes.Room[] {
-    const updatedRooms: roomTypes.Room[] = [];
-    
-    for (const [roomId, room] of this.rooms.entries()) {
-      const playerIndex = room.players.findIndex(p => p.id === socketId);
-      if (playerIndex !== -1) {
-        room.players.splice(playerIndex, 1);
-        console.log("[RoomManager] player left", {
-          roomId,
-          socketId,
-          totalPlayers: room.players.length
-        });
-        
-        if (room.players.length === 0) {
-          // 空ルーム削除
-          this.rooms.delete(roomId);
-          console.log("[RoomManager] deleted room", { roomId });
-        } else {
-          // オーナー切断時所有権移譲処理
-          if (room.ownerId === socketId) {
-            room.ownerId = room.players[0].id;
-            room.players[0].isOwner = true;
-            console.log("[RoomManager] transferred ownership", {
-              roomId,
-              newOwnerId: room.ownerId
-            });
-          }
-          updatedRooms.push(room);
-        }
-      }
-    }
-    return updatedRooms;
+    return this.roomExitService.removePlayer(socketId);
   }
 
   // オーナーIDからルームを取得
   public getRoomByOwnerId(ownerId: string): roomTypes.Room | undefined {
-    for (const room of this.rooms.values()) {
-      if (room.ownerId === ownerId) {
-        return room;
-      }
-    }
-    return undefined;
+    return this.roomQueryService.getRoomByOwnerId(ownerId);
   }
 }
\ No newline at end of file
diff --git a/apps/server/src/domains/room/application/adapters/createEmitToRoom.ts b/apps/server/src/domains/room/application/adapters/createEmitToRoom.ts
new file mode 100644
index 0000000..abab427
--- /dev/null
+++ b/apps/server/src/domains/room/application/adapters/createEmitToRoom.ts
@@ -0,0 +1,14 @@
+import { Server } from "socket.io";
+
+export type EmitToRoom = (roomId: string, event: string, payload?: unknown) => void;
+
+export const createEmitToRoom = (io: Server): EmitToRoom => {
+  return (roomId, event, payload) => {
+    if (payload === undefined) {
+      io.to(roomId).emit(event);
+      return;
+    }
+
+    io.to(roomId).emit(event, payload);
+  };
+};
diff --git a/apps/server/src/domains/room/application/services/RoomExitService.ts b/apps/server/src/domains/room/application/services/RoomExitService.ts
new file mode 100644
index 0000000..9fcdc6e
--- /dev/null
+++ b/apps/server/src/domains/room/application/services/RoomExitService.ts
@@ -0,0 +1,42 @@
+import type { roomTypes } from "@repo/shared";
+
+export class RoomExitService {
+  constructor(private rooms: Map<string, roomTypes.Room>) {}
+
+  public removePlayer(socketId: string): roomTypes.Room[] {
+    const updatedRooms: roomTypes.Room[] = [];
+
+    for (const [roomId, room] of this.rooms.entries()) {
+      const playerIndex = room.players.findIndex((player) => player.id === socketId);
+      if (playerIndex === -1) {
+        continue;
+      }
+
+      room.players.splice(playerIndex, 1);
+      console.log("[RoomManager] player left", {
+        roomId,
+        socketId,
+        totalPlayers: room.players.length,
+      });
+
+      if (room.players.length === 0) {
+        this.rooms.delete(roomId);
+        console.log("[RoomManager] deleted room", { roomId });
+        continue;
+      }
+
+      if (room.ownerId === socketId) {
+        room.ownerId = room.players[0].id;
+        room.players[0].isOwner = true;
+        console.log("[RoomManager] transferred ownership", {
+          roomId,
+          newOwnerId: room.ownerId,
+        });
+      }
+
+      updatedRooms.push(room);
+    }
+
+    return updatedRooms;
+  }
+}
diff --git a/apps/server/src/domains/room/application/services/RoomJoinService.ts b/apps/server/src/domains/room/application/services/RoomJoinService.ts
new file mode 100644
index 0000000..3fe81b1
--- /dev/null
+++ b/apps/server/src/domains/room/application/services/RoomJoinService.ts
@@ -0,0 +1,38 @@
+import { config, roomConsts } from "@repo/shared";
+import type { roomTypes } from "@repo/shared";
+
+export class RoomJoinService {
+  constructor(private rooms: Map<string, roomTypes.Room>) {}
+
+  public addPlayerToRoom(roomId: string, socketId: string, playerName: string): roomTypes.Room {
+    let room = this.rooms.get(roomId);
+    if (!room) {
+      room = {
+        roomId,
+        ownerId: socketId,
+        players: [],
+        status: roomConsts.RoomPhase.WAITING,
+        maxPlayers: config.GAME_CONFIG.MAX_PLAYERS_PER_ROOM,
+      };
+      this.rooms.set(roomId, room);
+      console.log("[RoomManager] created room", { roomId, ownerId: socketId });
+    }
+
+    const newPlayer: roomTypes.RoomMember = {
+      id: socketId,
+      name: playerName,
+      isOwner: room.ownerId === socketId,
+      isReady: false,
+    };
+
+    room.players.push(newPlayer);
+    console.log("[RoomManager] player joined", {
+      roomId,
+      socketId,
+      playerName,
+      totalPlayers: room.players.length,
+    });
+
+    return room;
+  }
+}
diff --git a/apps/server/src/domains/room/application/services/RoomQueryService.ts b/apps/server/src/domains/room/application/services/RoomQueryService.ts
new file mode 100644
index 0000000..3ad5dc2
--- /dev/null
+++ b/apps/server/src/domains/room/application/services/RoomQueryService.ts
@@ -0,0 +1,15 @@
+import type { roomTypes } from "@repo/shared";
+
+export class RoomQueryService {
+  constructor(private rooms: Map<string, roomTypes.Room>) {}
+
+  public getRoomByOwnerId(ownerId: string): roomTypes.Room | undefined {
+    for (const room of this.rooms.values()) {
+      if (room.ownerId === ownerId) {
+        return room;
+      }
+    }
+
+    return undefined;
+  }
+}