oil sump 29 accommodated in the outer casing 28 is the actual pump 31 a rotary vane vacuum pump 31 with two stages 11 and 13 it comprises three discs 32 33 34 with pump rings 35 36 accommodated in between the pump rings 35 36 form of the pump chambers 37 38 in which there is located one each eccentrically arranged rotor 41 respectively 42 with its vanes 43 respectively 44 the rotor 42 is linked to the shaft 45 of a drive motor not depicted moreover the bearing stubs of the rotors 41 42 are linked to each other in the area of the disk 33 the diameter of the rotors 41 42 is equal their lengths are different thus there result for the two pump stages 11 13 different pumping capacities when employing the presented pump as a two stage vacuum pump with series connected pump stages 11 13 the longer pump stage forms the inlet pump stage and the shorter one the delivery pump stage the pump 5 presented has been modified such that the pump stages 11 13 may be operated in parallel the inlet equipped with an anti suck back valve 46 which is present in any case in pumping stage 11 serves as inlet 14 the outlet of pumping stage 11 not depicted in detail is no longer linked to the inlet of the pumping stage 13 but instead opens out below the felt hat 47 the pumping stage 13 has been equipped with an independent intake port 48 forming the inlet.