A covering device for the load space of a motor vehicle, having a flexible surface structure, is held, in a rollable or extendable manner, on a winding shaft supported solidly with the loading space. A coiled spring apparatus for exerting the force for rolling up onto the surface structure is provided on the winding shaft. A form-stable extending element is positioned on one frontal end area of the surface structure. The surface structure is guided over its path of extension within the load space by a guiding device, in that at least one locking device for blocking the surface structure relative to the guiding device is provided in at least one partially-extended working position, and in that a manually-triggerable releasing device, by which the locking of the surface structure can be ended, is provided for the locking device.