diff --git a/ISCamRecorder/MainForm.Designer.cs b/ISCamRecorder/MainForm.Designer.cs
index 7ccb37e..1a47b16 100644
--- a/ISCamRecorder/MainForm.Designer.cs
+++ b/ISCamRecorder/MainForm.Designer.cs
@@ -450,12 +450,16 @@
             // 
             // chart1
             // 
+            this.chart1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
+            | System.Windows.Forms.AnchorStyles.Left) 
+            | System.Windows.Forms.AnchorStyles.Right)));
+            chartArea1.AxisX.LabelStyle.Format = "hh:mm:ss";
             chartArea1.Name = "ChartArea1";
             this.chart1.ChartAreas.Add(chartArea1);
             this.chart1.Location = new System.Drawing.Point(3, 3);
             this.chart1.Name = "chart1";
             series1.ChartArea = "ChartArea1";
-            series1.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Line;
+            series1.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.FastLine;
             series1.Name = "Series1";
             series1.XValueType = System.Windows.Forms.DataVisualization.Charting.ChartValueType.Time;
             series1.YValueType = System.Windows.Forms.DataVisualization.Charting.ChartValueType.Int32;
diff --git a/ISCamRecorder/MainForm.cs b/ISCamRecorder/MainForm.cs
index e6f1bf2..fa96034 100644
--- a/ISCamRecorder/MainForm.cs
+++ b/ISCamRecorder/MainForm.cs
@@ -26,6 +26,8 @@
         Task _SerialThread;             // シリアル通信スレッド
         float _TriggerFrameRate = 30.0F;
         private ulong _availablePhysicalMemory; //合計物理メモリ
+        Queue<int> _SensorValues = new Queue<int>();
+        Queue<DateTime> _SensorTime = new Queue<DateTime>();
 
         /// <summary>
         /// コンストラクタ
@@ -102,23 +104,41 @@
             serialPort1.RtsEnable = true;
             serialPort1.PortName = portname;
             serialPort1.Open();
-            Debug.WriteLine(portname);
+            Debug.WriteLine($"Serial Connect {portname}");
             while (!_ExitSignal) {
                 var str = serialPort1.ReadLine();
+                if (_ExitSignal) break;
                 var val = int.Parse(str);
                 var dt = DateTime.Now;
-                AddPoint(dt, val);
+                _SensorValues.Enqueue(val);
+                _SensorTime.Enqueue(dt);
+                if (_SensorValues.Count > 100) {
+                    _SensorValues.Dequeue();
+                    _SensorTime.Dequeue();
+                }
+                if (!_ExitSignal) Plot();
             }
         }
 
-        private void AddPoint(DateTime dt, int value) {
-            if (this.InvokeRequired) {
-                this.Invoke((MethodInvoker)delegate { AddPoint(dt, value); });
+        /// <summary>
+        /// グラフをプロット
+        /// </summary>
+        private void Plot() {
+            if (!this.IsDisposed && this.InvokeRequired) {
+                this.Invoke((MethodInvoker)delegate { Plot(); });
                 return;
             }
-            chart1.Series[0].Points.AddXY(dt, value);
+            chart1.Series[0].Points.Clear();
+            for (var i = 0; i < _SensorValues.Count; i++) {
+                chart1.Series[0].Points.AddXY(
+                    _SensorTime.ElementAt(i), _SensorValues.ElementAt(i));
+            }
         }
 
+        /// <summary>
+        /// シリアルポート取得
+        /// </summary>
+        /// <returns></returns>
         private string GetSerialPort() {
             var portname = "";
             var mcW32SerPort = new ManagementClass("Win32_SerialPort");
@@ -184,10 +204,11 @@
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void MainForm_FormClosing(object sender, FormClosingEventArgs e) {
+            serialPort1.Close();
             _ExitSignal = true;
             _UITimer.Dispose();
             _TriggerThread.Wait();
-            _SerialThread.Wait();
+            _SerialThread.Wait(1000);
         }
 
         /// <summary>