diff --git a/Covid19Radar/Tests/Covid19Radar.UnitTests/Services/Logs/LoggerServiceTests.cs b/Covid19Radar/Tests/Covid19Radar.UnitTests/Services/Logs/LoggerServiceTests.cs
index 4b8f9aa5f..8be14dc12 100644
--- a/Covid19Radar/Tests/Covid19Radar.UnitTests/Services/Logs/LoggerServiceTests.cs
+++ b/Covid19Radar/Tests/Covid19Radar.UnitTests/Services/Logs/LoggerServiceTests.cs
@@ -3,8 +3,10 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 using System;
+using System.Collections.Generic;
 using System.IO;
-using System.Text.RegularExpressions;
+using System.Linq;
+using System.Text;
 using System.Threading.Tasks;
 using Covid19Radar.Services;
 using Covid19Radar.Services.Logs;
@@ -753,10 +755,82 @@ private void RecreateLogsFile()
 
         private string[] ParseLogRow(string logRow)
         {
-            var pattern = new Regex(",(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)");
-            return pattern.Split(logRow);
+            return ParseCsv(logRow, false)
+                .Select(s => $"\"{s}\"")
+                .ToArray();
         }
 
         #endregion
+
+        #region CocoaLogViewer Code
+
+        // このコードは CocoaLogViewer からコピーしました。MITライセンスに基づいて配布されています。
+        // This source code is copied from CocoaLogViewer and distributed under the MIT License.
+        // https://github.com/YigtyORG/CocoaLogViewer/blob/00862602b739d3c4f6c9c129e9fe0a6ad32cbeed/src/Covid19Radar.LogViewer/Models/LogFileModel.cs#L64-L123
+        // Copyright (C) 2020-2021 Yigty.ORG; all rights reserved.
+        // Copyright (C) 2020-2021 Takym.
+
+		private static List<string> ParseCsv(string line, bool allowEscape)
+		{
+			var  result = new List<string>();
+			var  sb     = new StringBuilder(); // This line was modified.
+			int  i      = 0;
+			bool dq     = false;
+			while (i < line.Length) {
+				char ch = line[i];
+				switch (ch) {
+				case '\"':
+					++i;
+					if (i < line.Length && line[i] == '\"') {
+						++i;
+						sb.Append('\"');
+					} else {
+						dq = !dq;
+					}
+					break;
+				case '\\' when allowEscape:
+					++i;
+					if (i < line.Length) {
+						ch = line[i];
+						++i;
+						sb.Append(ch switch {
+							't' => '\t',
+							'v' => '\v',
+							'r' => '\r',
+							'n' => '\n',
+							_ => ch
+						});
+					} else {
+						sb.Append('\\');
+					}
+					break;
+				case ',':
+					++i;
+					if (dq) {
+						sb.Append(',');
+					} else {
+						result.Add(sb.ToString());
+						sb.Clear();
+					}
+					break;
+				case ' ': case '\0': case '\t': case '\v': case '\r': case '\n':
+					++i;
+					if (dq) {
+						sb.Append(ch);
+					}
+					break;
+				default:
+					++i;
+					sb.Append(ch);
+					break;
+				}
+			}
+			if (sb.Length > 0) {
+				result.Add(sb.ToString());
+			}
+			return result;
+		}
+
+        #endregion
     }
 }