ASP.NET Excel Response.ContentType = "application/vnd.ms-excel"

Response.ContentType = "application/vnd.ms-excel"

<%@ Page Language="VB" %>
<script runat="server">
    Sub Page_Load(sender As Object, e As EventArgs)
		Response.Clear()
		Response.AddHeader("Content-Disposition", "Attachment;Filename=Excel.xls")
		Response.Buffer = True
		Response.Charset = "UTF-8"
		Response.ContentType = "application/vnd.ms-excel"

		Response.write("<table width=500  border=1>")
		Response.write("  <tr>")
		Response.write("	<td>Column1</td>")
		Response.write("	<td>Column2</td>")
		Response.write("	<td>Column3</td>")
		Response.write("  </tr>")
		Response.write("  <tr>")
		Response.write("	<td>1</td>")
		Response.write("	<td>2</td>")
		Response.write("	<td>3</td>")
		Response.write("  </tr>")
		Response.write("  <tr>")
		Response.write("	<td>4</td>")
		Response.write("	<td>5</td>")
		Response.write("	<td>6</td>")
		Response.write("  </tr>")
		Response.write("</table>")
	End Sub
</script>