Abstract: In a vane compressor, a liner formed of iron or an alloy thereof is disposed along the endless camming inner peripheral surface of the cylinder forming part of the pump housing. The liner has at least one break extending thereacross and has its whole surface elastically permanently urging the cylinder in the radially outward directions. The use of the liner permits forming the rotor and the cylinder of aluminum or an alloy thereof. Preferably, the cylinder has its camming inner peripheral surface formed with a pair of elongate recesses extending parallel with the axis of the rotor and diametrically symmetrically arranged. The recesses are supplied with pumped compression fluid. The liner is partially urged by the rotor and located in the above recesses to maintain fluid tightness between the suction side and the discharge side in the pump housing.