diff --git a/Cafe.Matcha/Views/MainControl.xaml.cs b/Cafe.Matcha/Views/MainControl.xaml.cs
index 750c4a1..39c4546 100644
--- a/Cafe.Matcha/Views/MainControl.xaml.cs
+++ b/Cafe.Matcha/Views/MainControl.xaml.cs
@@ -277,7 +277,8 @@ private void Log(LogType type, char level, string message)
             }
 
             string typeString = Enum.GetName(typeof(LogType), type);
-            vm.Log = string.Format("[{0}][{1}][{2}] {3}\r\n", DateTime.Now, level, typeString, message) + vm.Log;
+            vm.Log = string.Format("[{0}][{1}][{2}] {3}\r\n", DateTime.Now, level, typeString, message) +
+                (vm.Log.Length > 10240 ? vm.Log.Substring(0, 10240) : vm.Log);
             ++vm.LogShowCount;
         }