A vacuum pump, in particular a pump of the type with rolling bodies, includes rotary bodies (12) arranged in a suction chamber (10). The pressure side (30) of the pump is connected to the suction side (20) by a connecting channel (22). In the connecting channel (22), a valve (24) is arranged which closes a through opening (32). On exceeding a set pressure difference between the pressure side (30) and the suction side (20), the valve opens automatically. In order to reduce the necessary space and to reduce the switching noise from the valve, the valve body is embodied as a valve flap (28).