Imports System.IO
Imports System.IO.Compression
Module Module1
    Sub Main()
        Dim zipPath As String = "c:\example\start.zip"
        Dim extractPath As String = "c:\example\extract"
        '                vvvvvvvvvv unbekannt  
        Using archive As ZipArchive = ZipFile.OpenRead(zipPath)
            For Each entry As ZipArchiveEntry In archive.Entries
                If entry.FullName.EndsWith(".txt", _
                  StringComparison.OrdinalIgnoreCase) Then
                    entry.ExtractToFile(Path.Combine(extractPath, _
                    entry.FullName))
                End If
            Next
        End Using
    End Sub
End Module