The invention relates to a compressed-gas firearm (1), in particular a multiple-shot pistol, characterized by a novel valve system (39) for the pulsed release of compressed gas when firing a shot. The valve system (39) comprises two separately acting sealing devices, which are located opposite each other in the frontal end area of the valve chamber (19). The sealing devices both comprise one sealing ring each (22, 23), whose shape and position, in cooperation with the axially movable valve push rod (15), have a self-cleaning effect.