diff --git a/LogInsights/LogInsights.csproj b/LogInsights/LogInsights.csproj
index f88c250..eedfc69 100644
--- a/LogInsights/LogInsights.csproj
+++ b/LogInsights/LogInsights.csproj
@@ -17,7 +17,7 @@
     <Compile Remove="TextReading\ReadLogByBlock.cs" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.ApplicationInsights.Query" Version="1.0.0" />
+    <PackageReference Include="Azure.Monitor.Query" Version="1.5.0" />
     <PackageReference Include="GitVersion.MsBuild" Version="6.1.0">
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>
diff --git a/LogInsights/LogReader/Implementations/AppInsightsLogReader.cs b/LogInsights/LogReader/Implementations/AppInsightsLogReader.cs
index 21387bb..47c6d16 100644
--- a/LogInsights/LogReader/Implementations/AppInsightsLogReader.cs
+++ b/LogInsights/LogReader/Implementations/AppInsightsLogReader.cs
@@ -2,7 +2,11 @@
 using CsvHelper.Configuration.Attributes;
 
 using LogInsights.Helpers;
-using Microsoft.Azure.ApplicationInsights.Query;
+using Azure.Core;
+using Azure.Identity;
+using Azure.Monitor.Query;
+using Azure.Monitor.Query.Models;
+using System.Net.Http;
 using System;
 using System.Collections.Generic;
 using System.Globalization;
@@ -15,11 +19,32 @@
 
 // ReSharper disable UnusedMember.Local
 
-namespace LogInsights.LogReader
-{
+namespace LogInsights.LogReader
+{
+    // Custom TokenCredential for Application Insights API key authentication
+    internal class AppInsightsApiKeyCredential : TokenCredential
+    {
+        private readonly string _apiKey;
+
+        public AppInsightsApiKeyCredential(string apiKey)
+        {
+            _apiKey = apiKey ?? throw new ArgumentNullException(nameof(apiKey));
+        }
+
+        public override AccessToken GetToken(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        {
+            // Return the API key as a bearer token - this may need adjustment based on actual Azure.Monitor.Query implementation
+            return new AccessToken(_apiKey, DateTimeOffset.UtcNow.AddHours(1));
+        }
+
+        public override ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        {
+            return new ValueTask<AccessToken>(GetToken(requestContext, cancellationToken));
+        }
+    }
     public class AppInsightsLogReader : LogReader
     {
-        private readonly ApplicationInsightsDataClient _client;
+        private readonly LogsQueryClient _client;
         private readonly AppInsightsLogReaderConnectionStringBuilder _connString;
 
         private static readonly JsonSerializerOptions _jsonOptions = new(JsonSerializerDefaults.General) {
@@ -92,8 +117,13 @@ public AppInsightsLogReader(AppInsightsLogReaderConnectionStringBuilder connecti
                 if ( string.IsNullOrEmpty(apiKey) )
                     throw new Exception($"Missing {nameof(apiKey)} value.");
 
-                _client = new ApplicationInsightsDataClient(new ApiKeyClientCredentials(apiKey));
-                Display = $"App Insights Reader - {_client.BaseUri.OriginalString}";
+                // Create LogsQueryClient for Application Insights
+                // Note: Application Insights now uses Log Analytics workspace under the hood
+                // API key authentication is handled via custom credential
+                var credential = new AppInsightsApiKeyCredential(apiKey);
+                var options = new LogsQueryClientOptions();
+                _client = new LogsQueryClient(credential, options);
+                Display = $"App Insights Reader - {appId}";
             }
             else
             {
@@ -175,84 +205,96 @@ protected override async IAsyncEnumerable<LogEntry> OnReadAsync(
             }
         }
 
-        private async IAsyncEnumerable<_Row> _ReadAppInsightsDataAsync([EnumeratorCancellation] CancellationToken ct)
-        {
-            var events = new Events(_client);
-
-            var result = await events.Client.Query.ExecuteAsync(
-                    _connString.AppId,
-                    _connString.Query,
-                    !string.IsNullOrEmpty(_connString.TimeSpan) ? _connString.TimeSpan : null,
-                    cancellationToken: ct)
-                .ConfigureAwait(false);
-
-            if (result.Tables.Count < 1)
-                throw new Exception("Missing result table");
-
-            var table = result.Tables[0];
-
-            int timestampIdx = -1;
-            int messageIdx = -1;
-            int severityIdx = -1;
-            int itemIdIdx = -1;
-            int customDimensionsIdx = -1;
-            int outerMessageIdx = -1;
-            int detailsIdx = -1;
-
-            for (var i = 0; i < table.Columns.Count; i++)
-            {
-                var column = table.Columns[i];
-
-                switch (column.Name)
-                {
-                    case "itemId":
-                        itemIdIdx = i;
-                        break;
-
-                    case "timestamp":
-                        timestampIdx = i;
-                        break;
-
-                    case "message":
-                        messageIdx = i;
-                        break;
-
-                    case "severityLevel":
-                        severityIdx = i;
-                        break;
-
-                    case "customDimensions":
-                        customDimensionsIdx = i;
-                        break;
-
-                    case "outerMessage":
-                        outerMessageIdx = i;
-                        break;
-
-                    case "details":
-                        detailsIdx = i;
-                        break;
-                }
-            }
-
-            if (timestampIdx < 0 ||
-                messageIdx < 0 ||
-                itemIdIdx < 0)
-                throw new Exception("Missing columns");
-
-            foreach (var row in table.Rows)
-            {
-                yield return new _Row
-                    {
-                        ItemId = (string)row[itemIdIdx],
-                        TimeStamp = (DateTime)row[timestampIdx],
-                        Message = (string)row[messageIdx],
-                        Severity = severityIdx > -1 ? (long)row[severityIdx] : 1L,
-                        CustomDimensions = customDimensionsIdx > -1 ? (string)row[customDimensionsIdx] : "",
-                        Details = detailsIdx > -1 ? (string)row[detailsIdx] : "",
-                        OuterMessage = detailsIdx > -1 ? (string)row[outerMessageIdx] : ""
-                };
-            }
+        private async IAsyncEnumerable<_Row> _ReadAppInsightsDataAsync([EnumeratorCancellation] CancellationToken ct)
+        {
+            QueryTimeRange timeRange = QueryTimeRange.All;
+            if (!string.IsNullOrEmpty(_connString.TimeSpan))
+            {
+                // Try to parse the timespan - the old API used formats like "P1D" (ISO 8601 duration)
+                // The new API expects QueryTimeRange or TimeSpan objects
+                if (TimeSpan.TryParse(_connString.TimeSpan, out var parsedTimespan))
+                {
+                    timeRange = new QueryTimeRange(parsedTimespan);
+                }
+                else
+                {
+                    // Try parsing as ISO 8601 duration or use default
+                    timeRange = QueryTimeRange.All;
+                }
+            }
+
+            var result = await _client.QueryWorkspaceAsync(
+                    _connString.AppId,
+                    _connString.Query,
+                    timeRange,
+                    cancellationToken: ct)
+                .ConfigureAwait(false);
+
+            var table = result.Value.Table;
+
+            int timestampIdx = -1;
+            int messageIdx = -1;
+            int severityIdx = -1;
+            int itemIdIdx = -1;
+            int customDimensionsIdx = -1;
+            int outerMessageIdx = -1;
+            int detailsIdx = -1;
+
+            for (var i = 0; i < table.Columns.Count; i++)
+            {
+                var column = table.Columns[i];
+
+                switch (column.Name)
+                {
+                    case "itemId":
+                        itemIdIdx = i;
+                        break;
+
+                    case "timestamp":
+                        timestampIdx = i;
+                        break;
+
+                    case "message":
+                        messageIdx = i;
+                        break;
+
+                    case "severityLevel":
+                        severityIdx = i;
+                        break;
+
+                    case "customDimensions":
+                        customDimensionsIdx = i;
+                        break;
+
+                    case "outerMessage":
+                        outerMessageIdx = i;
+                        break;
+
+                    case "details":
+                        detailsIdx = i;
+                        break;
+                }
+            }
+
+            if (timestampIdx < 0 ||
+                messageIdx < 0 ||
+                itemIdIdx < 0)
+                throw new Exception("Missing columns");
+
+            foreach (var row in table.Rows)
+            {
+                yield return new _Row
+                    {
+                        ItemId = row[itemIdIdx]?.ToString(),
+                        TimeStamp = row[timestampIdx] is DateTimeOffset dto ? dto.DateTime : 
+                                   DateTime.TryParse(row[timestampIdx]?.ToString(), out var dt) ? dt : DateTime.MinValue,
+                        Message = row[messageIdx]?.ToString(),
+                        Severity = severityIdx > -1 && long.TryParse(row[severityIdx]?.ToString(), out var sev) ? sev : 1L,
+                        CustomDimensions = customDimensionsIdx > -1 ? row[customDimensionsIdx]?.ToString() : "",
+                        Details = detailsIdx > -1 ? row[detailsIdx]?.ToString() : "",
+                        OuterMessage = outerMessageIdx > -1 ? row[outerMessageIdx]?.ToString() : ""
+                };
+            }
         }
 
         private async IAsyncEnumerable<_Row> _ReadCsvDataAsync()