FIELD: printing equipment. SUBSTANCE: device has chain conveyor for sheets which are to be checked. Support rods through which checked sheet is transported are equipped in checking region with suction nozzles. Mobile cantilevers are located in space between two support rods. They are also equipped with suction nozzles and are arranged in one line in working position together with suction nozzles of support rods. They are located in plane of sheet movement in order to keep checked sheets in this plane. Touch with clamps which draw sheets is prevented by means of unit which turns said cantilevers away when clamps pass over cantilevers. EFFECT: quality check without affecting of flat newly- printed sheets. 7 cl, 4 dwg
