diff --git a/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts b/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
index 637ded1..a91dce1 100644
--- a/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
+++ b/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
@@ -3,8 +3,10 @@
  * ゲーム系ユースケースが利用する入力ポートと出力ポートの契約を定義する
  */
 import type {
+  BombPlacedPayload,
   gameTypes,
   playerTypes,
+  PlaceBombPayload,
   roomTypes,
   CurrentPlayersPayload,
   GameResultPayload,
@@ -49,6 +51,11 @@
   movePlayer(id: string, x: number, y: number): void;
 }
 
+/** 爆弾設置ユースケースが利用するルーム解決入力ポート */
+export interface PlaceBombRoomPort {
+  getRoomByPlayerId(playerId: string): roomTypes.Room | undefined;
+}
+
 /** 切断ユースケースが利用するプレイヤー削除入力ポート */
 export interface DisconnectPlayerPort {
   removePlayer(id: string): void;
@@ -70,5 +77,19 @@
   publishGameStartToRoom(roomId: roomTypes.Room["roomId"], payload: GameStartPayload): void;
   publishCurrentPlayersToSocket(players: CurrentPlayersPayload): void;
   publishGameStartToSocket(payload: GameStartPayload): void;
+  publishBombPlacedToRoom(roomId: roomTypes.Room["roomId"], payload: BombPlacedPayload): void;
   publishPlayerRemovedToRoom(roomId: roomTypes.Room["roomId"], removedPlayerId: RemovePlayerPayload): void;
 }
+
+/** 爆弾設置ユースケースが利用する爆弾状態管理入力ポート */
+export interface BombPlacementStorePort {
+  shouldBroadcastBombPlaced(roomId: string, dedupeKey: string, nowMs: number): boolean;
+  issueServerBombId(roomId: string): string;
+}
+
+/** 爆弾設置ユースケースの入力値 */
+export type PlaceBombInput = {
+  socketId: string;
+  payload: PlaceBombPayload;
+  nowMs: number;
+};
diff --git a/apps/server/src/domains/game/application/useCases/placeBombUseCase.ts b/apps/server/src/domains/game/application/useCases/placeBombUseCase.ts
new file mode 100644
index 0000000..2e4b822
--- /dev/null
+++ b/apps/server/src/domains/game/application/useCases/placeBombUseCase.ts
@@ -0,0 +1,41 @@
+/**
+ * placeBombUseCase
+ * 爆弾設置入力を検証済み前提で処理し，ルーム配信を実行する
+ */
+import type {
+  BombPlacementStorePort,
+  GameOutputPort,
+  PlaceBombInput,
+  PlaceBombRoomPort,
+} from "../ports/gameUseCasePorts";
+
+type PlaceBombUseCaseParams = {
+  roomResolver: PlaceBombRoomPort;
+  bombStore: BombPlacementStorePort;
+  input: PlaceBombInput;
+  output: Pick<GameOutputPort, "publishBombPlacedToRoom">;
+};
+
+/** 爆弾設置入力を重複排除と採番付きでルームへ配信する */
+export const placeBombUseCase = ({
+  roomResolver,
+  bombStore,
+  input,
+  output,
+}: PlaceBombUseCaseParams): void => {
+  const roomId = roomResolver.getRoomByPlayerId(input.socketId)?.roomId;
+  if (!roomId) {
+    return;
+  }
+
+  const dedupeKey = `${input.socketId}:${input.payload.requestId}`;
+  if (!bombStore.shouldBroadcastBombPlaced(roomId, dedupeKey, input.nowMs)) {
+    return;
+  }
+
+  output.publishBombPlacedToRoom(roomId, {
+    ...input.payload,
+    bombId: bombStore.issueServerBombId(roomId),
+    ownerId: input.socketId,
+  });
+};
diff --git a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
index bfa4b8f..3594a06 100644
--- a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
+++ b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
@@ -5,6 +5,7 @@
 import { Server } from "socket.io";
 import { protocol } from "@repo/shared";
 import type {
+  BombPlacedPayload,
   GameStartPayload,
   GameResultPayload,
   PongPayload,
@@ -53,6 +54,9 @@
     publishGameStartToSocket: (payload: GameStartPayload) => {
       common.emitToSocket(protocol.SocketEvents.GAME_START, payload);
     },
+    publishBombPlacedToRoom: (roomId: RoomId, payload: BombPlacedPayload) => {
+      common.emitToRoom(roomId, protocol.SocketEvents.BOMB_PLACED, payload);
+    },
   };
 };
 
diff --git a/apps/server/src/network/handlers/game/registerGameHandlers.ts b/apps/server/src/network/handlers/game/registerGameHandlers.ts
index 75ea885..577b8cb 100644
--- a/apps/server/src/network/handlers/game/registerGameHandlers.ts
+++ b/apps/server/src/network/handlers/game/registerGameHandlers.ts
@@ -7,13 +7,16 @@
 import { readyForGameCoordinator } from "@server/application/coordinators/readyForGameCoordinator";
 import { startGameCoordinator } from "@server/application/coordinators/startGameCoordinator";
 import type {
+  BombPlacementStorePort,
   MovePlayerPort,
+  PlaceBombRoomPort,
   ReadyForGamePort,
   ReadyForGameRoomPort,
   StartGamePort,
   StartGameRoomPort,
 } from "@server/domains/game/application/ports/gameUseCasePorts";
 import { movePlayerUseCase } from "@server/domains/game/application/useCases/movePlayerUseCase";
+import { placeBombUseCase } from "@server/domains/game/application/useCases/placeBombUseCase";
 import { pingUseCase } from "@server/domains/game/application/useCases/pingUseCase";
 import { createCommonHandlerContext } from "@server/network/handlers/CommonHandler";
 import { isMovePayload, isPingPayload, isPlaceBombPayload } from "@server/network/validation/socketPayloadValidators";
@@ -34,7 +37,7 @@
   io: Server,
   socket: Socket,
   gameManager: StartGamePort & ReadyForGamePort & MovePlayerPort,
-  roomManager: StartGameRoomPort & ReadyForGameRoomPort
+  roomManager: StartGameRoomPort & ReadyForGameRoomPort & PlaceBombRoomPort
 ) => {
   const common = createCommonHandlerContext(io, socket);
   const gameOutputAdapter = createGameOutputAdapter(common);
@@ -107,23 +110,20 @@
       return;
     }
 
-    const roomId = roomManager.getRoomByPlayerId(socket.id)?.roomId;
-    if (!roomId) {
-      return;
-    }
-
-    const nowMs = Date.now();
-    const dedupeKey = `${socket.id}:${data.requestId}`;
-    if (!shouldBroadcastBombPlaced(roomId, dedupeKey, nowMs)) {
-      return;
-    }
-
-    const payload = {
-      ...data,
-      bombId: issueServerBombId(roomId),
-      ownerId: socket.id,
+    const bombStore: BombPlacementStorePort = {
+      shouldBroadcastBombPlaced,
+      issueServerBombId,
     };
 
-    common.emitToRoom(roomId, protocol.SocketEvents.BOMB_PLACED, payload);
+    placeBombUseCase({
+      roomResolver: roomManager,
+      bombStore,
+      input: {
+        socketId: socket.id,
+        payload: data,
+        nowMs: Date.now(),
+      },
+      output: gameOutputAdapter,
+    });
   });
 };