1. Click your desired target folder in the Workspace pane.
2. Click 
on the toolbar, then select Folder... from the drop-down menu;
Or, go to File --> New --> Folder... from the top menu.
3. Enter the folder name in the Create folder form.
4. Click Create to complete creating your new folder.
Note
If any file is selected in the Workspace pane, there will be a folder created in the parent folder of this file.
In case no item is selected in the Workspace pane, the created folder is placed in the root folder.
In case of multiple selections, this function is disabled.