Vacuum system, comprising a vacuum pump, preferably turbomolecular pump, and at least one vacuum chamber, wherein the vacuum pump comprises: at least a first and a second inlet (18, 20) and a common outlet; at least a first and a second pumping stage (24, 26), each pumping stage (24, 26) comprising at least one rotor element being arranged on a common rotor shaft, wherein the first inlet is connected to an upstream end of the first pumping stage and the second inlet is connected to an upstream end of the second pumping stage; a direction element (34, 52, 66) for preventing a gas flow from a downstream end of the first pumping stage to the second inlet; a conduit having a conduit inlet and a conduit outlet, wherein the conduit inlet is connected to the downstream end of the first pumping stage and the conduit outlet is connected to a location downstream of the second pumping stage; wherein the first inlet and the second inlet of the pump are connected to the same vacuum chamber, wherein the pump comprises a third pumping stage wherein the downstream end of the second pumping stage and/or the conduit outlet are connected to an upstream end of the third pumping stage and characterized in that the third pumping stage comprises at least one rotor element arranged on the common shaft. wherein the vacuum pump comprises: at least a first and a second inlet (18, 20) and a common outlet; at least a first and a second pumping stage (24, 26), each pumping stage (24, 26) comprising at least one rotor element being arranged on a common rotor shaft, wherein the first inlet is connected to an upstream end of the first pumping stage and the second inlet is connected to an upstream end of the second pumping stage; a direction element (34, 52, 66) for preventing a gas flow from a downstream end of the first pumping stage to the second inlet; a conduit having a conduit inlet and a conduit outlet, wherein the conduit inlet is connected to the downstream end of the first pumping stage and the conduit outlet is connected to a location downstream of the second pumping stage; at least a first and a second inlet (18, 20) and a common outlet; at least a first and a second pumping stage (24, 26), each pumping stage (24, 26) comprising at least one rotor element being arranged on a common rotor shaft, wherein the first inlet is connected to an upstream end of the first pumping stage and the second inlet is connected to an upstream end of the second pumping stage; a direction element (34, 52, 66) for preventing a gas flow from a downstream end of the first pumping stage to the second inlet; a conduit having a conduit inlet and a conduit outlet, wherein the conduit inlet is connected to the downstream end of the first pumping stage and the conduit outlet is connected to a location downstream of the second pumping stage; wherein the first inlet and the second inlet of the pump are connected to the same vacuum chamber, wherein the pump comprises a third pumping stage wherein the downstream end of the second pumping stage and/or the conduit outlet are connected to an upstream end of the third pumping stage and characterized in that the third pumping stage comprises at least one rotor element arranged on the common shaft.