The present invention relates to an apparatus (1) for evacuating a system (3), comprising a pump (5), the pump (5) being suitable for being in connection with the system (3) with its inlet (7), a pressure tank (11) and a directional control valve (13), the pump (5) transporting a medium out of the system (3) and the pressure tank (11) into an ambience when the pressure tank (11) is connected to its inlet (7), wherein the directional control valve (13) is configured to switch the pressure tank (11) from the inlet (7) to the outlet (9) of the pump (5) when a predefined criterion is fulfilled. The present invention further relates to a breast pump (31) device comprising an apparatus (1) for evacuating a system (3) and a receiving funnel (27) for receiving a breast of a woman.
