Low-pressure screw compressor provided with a rotor housing (2) with an inlet side and an outlet side, and enclosing two rotor bodies (3 and 4) including shafts (5, 7 respectively) and screws (6, 8 respectively) mounted on the shafts. The rotor shafts (5 or 7) are bearing-mounted in the rotor housing (2), with the bearing mountings on the inlet side of the rotor housing each using a single loose bearing and the bearing mountings on the outlet side of the rotor housing each using a single fixed cylindrical roller bearing. Spring devices acting on the bearing mountings at the inlet side urge the shafts and rotors toward the outlet side to maintain minimum clearance between the rotors and the housing at the outlet side of the rotors.