Private WithEvents oExl As New Excel.Application
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        oExl.Workbooks.Open(PATH)
        oExl.ActiveWorkbook.Sheets("Tabelle1").select()
        oExl.Visible = True
End Sub
Private Sub oExl_WorkbookBeforeClose(ByVal Wb As Excel.Workbook, ByRef Cancel _
  As Boolean) Handles oExl.WorkbookBeforeClose
        MsgBox("close")
End Sub