Abstract: A device for processing a usable surface extending on a usable side of a substrate (11) having a large surface area, particularly such having a length or width >0.5 m and a thickness <1 cm, through the substrate, has at least three bearing elements (21, 23, 25) disposed at a distance from each other for receiving the substrate (11), and a movable processing device for processing the substrate between the bearing elements from the rear of the substrate. The bearings support the substrate, and processing of the glass substrate can be carried out in the at least two intermediate regions between the bearing elements from the rear. At least one non-terminal bearing element is disposed displaceable or movable relative to the substrate in order to make the entire usable surface of the substrate accessible to the processing device by displacement or movement.