A suction device, having a suction unit for generating a suction flow and having a suction-device housing, in which a dirt-collecting chamber is arranged, which has a suction inlet and is flow-connected to the suction unit via at least one filter and a suction-extraction channel arrangement, wherein at least one external-air inlet, which can be closed by an external-air valve, is arranged on the suction-extraction channel arrangement between the filter and the suction unit, wherein the external-air valve has an external-air-valve body for closing the external-air inlet, which external-air-valve body can be moved, by movement of an actuating element along an actuation path. A transmission is arranged between the actuating element and the external-air-valve body, which transmission enables movement of the actuating element.