Roof module with a slidable panel and a rigid covering element

The roof module has an outer skin (22) with a slot (28) into which especially a holding element for a cover can enter that can be moved between open and closed positions. A rigid cover element (30) is movable between a closed position, in which it closes the slot, and an open position, in which it exposes the slot to the holding element. The cover element is underneath the outer skin when in the closed position.