diff --git a/src/main/java/info/istlab/ServerTester/MulticastReceiver.java b/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
index 8b5f9f1..d922a70 100644
--- a/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
+++ b/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
@@ -60,7 +60,7 @@
 
             if (remoteHostsWindow != null) {
                 remoteHostsWindow.updateData(addr, message);
-                remoteHostsWindow.frame.pack();
+                remoteHostsWindow.packIfNotResized();
             }
         }
     }
@@ -80,6 +80,8 @@
 
     public void openWindow() {
         if (remoteHostsWindow != null) {
+            remoteHostsWindow.autoPack = true;
+            remoteHostsWindow.packIfNotResized();
             remoteHostsWindow.frame.setVisible(true);
         } else {
             remoteHostsWindow = new RemoteHostsWindow(receivedData);
diff --git a/src/main/java/info/istlab/ServerTester/NetworkInterfaceSelector.java b/src/main/java/info/istlab/ServerTester/NetworkInterfaceSelector.java
index 8c4284f..36ea870 100644
--- a/src/main/java/info/istlab/ServerTester/NetworkInterfaceSelector.java
+++ b/src/main/java/info/istlab/ServerTester/NetworkInterfaceSelector.java
@@ -93,12 +93,12 @@
                 NetworkInterface networkInterface = interfaces.nextElement();
 
                 // インターフェース名と表示名を出力
-                System.out.println("Name: " + networkInterface.getName());
-                System.out.println("Display Name: " + networkInterface.getDisplayName());
-                System.out.println("Up: " + networkInterface.isUp());
-                System.out.println("Loopback: " + networkInterface.isLoopback());
-                System.out.println("Virtual: " + networkInterface.isVirtual());
-                System.out.println("Supports Multicast: " + networkInterface.supportsMulticast());
+                // System.out.println("Name: " + networkInterface.getName());
+                // System.out.println("Display Name: " + networkInterface.getDisplayName());
+                // System.out.println("Up: " + networkInterface.isUp());
+                // System.out.println("Loopback: " + networkInterface.isLoopback());
+                // System.out.println("Virtual: " + networkInterface.isVirtual());
+                // System.out.println("Supports Multicast: " + networkInterface.supportsMulticast());
                 // ループバックインターフェースは除外
                 if (networkInterface.isLoopback()) {
                     continue;
@@ -108,11 +108,11 @@
                 for (InterfaceAddress addr : addresses) {
                     InetAddress inetAddr = addr.getAddress();
                     if (inetAddr instanceof java.net.Inet4Address) { // IPv4 アドレスのみ
-                        System.out.println("IPv4 Address: " + inetAddr.getHostAddress());
+                        // System.out.println("IPv4 Address: " + inetAddr.getHostAddress());
                         ret.add(networkInterface);
                     }
                 }
-                System.out.println("----------------------------------------------------");
+                // System.out.println("----------------------------------------------------");
             }
         } catch (SocketException e) {
             e.printStackTrace();
diff --git a/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java b/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
index 381cee5..beaf172 100644
--- a/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
+++ b/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
@@ -2,6 +2,7 @@
 
 import java.awt.Color;
 import java.awt.Desktop;
+import java.awt.event.ComponentAdapter;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -19,6 +20,7 @@
     JTabbedPane tabbedPane;
     Hashtable<String, RemoteHostPanel> panels = new Hashtable<String, RemoteHostPanel>();
     JFrame frame;
+    boolean autoPack = true; // ウィンドウをリサイズしたら、falseにする。再度開いたときにtrueにする。
 
     public RemoteHostsWindow(Hashtable<String, String> receivedData) {
         frame = new JFrame();
@@ -31,6 +33,12 @@
                 frame.setVisible(false);
             }
         });
+        frame.addComponentListener(new ComponentAdapter() {
+            @Override
+            public void componentResized(java.awt.event.ComponentEvent e) {
+                autoPack = false;
+            }
+        });
 
         tabbedPane = new JTabbedPane();
         frame.getContentPane().add(tabbedPane);
@@ -60,6 +68,13 @@
             tabbedPane.add(addr, rhp);
             panels.put(addr, rhp);
         }
+        packIfNotResized();
+    }
+
+    public void packIfNotResized() {
+        if (autoPack) {
+            frame.pack();
+        }
     }
 }