I want to open a local folder from the web application I saw in Internet Explorer 11.

For security reasons, it is prohibited.If you are restricting it to Internet Explorer, you may be able to create ActiveX controls, install them on that machine, and run them.However, I don't think it's HTML anymore.

Chrome experimentally implements the Native File System API.Depending on the function you want to realize, you may be able to use it.

Finally, we decided to use ActiveX.
Click the button to open the C:\work folder.

<script type="text/javascript">

    var path="C:\\work";
    path.replace(/\u002f/g, '\\');

    function openExplorer(){
        varopenWorlder='explorer.exe/n, /e, /root, '+path;
        var ActiveXobj=new ActiveXObject("WScript.Shell");
        ActiveXobj.Run(openWorlder);
    }
</script>

<input type="button" value="button" onclick="openExplorer();">

Internet Explorer also requires registration with trusted sites.

Enable … even if you run the Internet Option > Trusted Sites > Custom Level > script.