Abstract: The invention9) relates to a screw vacuum pump (1) comprising shafts (7,8) and two rotors (3, 4)10) secured to the shafts, whereby each rotor has a central hollow chamber (31) provided with devices for circulating a coolant. In order to effectively cool the rotors (3, 4), built-in components rotating along with the rotor arc located in the chamber (31) of the rotors (3,4), said components forming a relatively narrow, annular slot segment (32) that is cross-flown by the coolant. The corresponding annular slot segment (32) extends between the built-in components and the corresponding inner wall of the rotor's hollow chamber (31) and between the suction side and the delivery side of the rotor (3,4). Supply of the annular slot segment (32) with coolant is carried out via separate feed lines and discharge lines traversing the shaft. Means are provided to ensure cavitation-free and bubble-free flow through the annular slot segment.