Hi Heiner, yes the built in way to deselect all with the keyboard is by the Esc key, which will also turn off other things as well like if control points for an object are turned on pushing escape will first turn those off, then you press it again to deselect all. If there are no special modes turned on then just one press of Esc will deselect.

If you want you can also set it up on a custom shortcut key by putting in the following as the command part of the shortcut key:

script: moi.geometryDatabase.deselectAll();

- Michael