diff --git a/src/main/java/info/istlab/ServerTester/TimeServer.java b/src/main/java/info/istlab/ServerTester/TimeServer.java
index 83b766c..9514527 100644
--- a/src/main/java/info/istlab/ServerTester/TimeServer.java
+++ b/src/main/java/info/istlab/ServerTester/TimeServer.java
@@ -31,6 +31,10 @@
 		// サーバ側の処理の繰り返し
 		while (thread != null) {
 			try {
+				if (serverSocket.isClosed()) {
+					thread = null;
+					break;
+				}
 				clientSocket = serverSocket.accept(); // 接続がくるまで、ここで待つ
 				System.out.println("(TimeServer) accepted (client has connected)");
 				System.out.println(clientSocket.getRemoteSocketAddress().toString());