A vane-type compressor of the lubrication type in which pressure applied to vane bottoms is controlled to prevent vane breakage and excessive wear. A rotor is disposed between a rotor housing and a pair of side housings with vanes slidingly disposed within corresponding vane grooves radially formed in the rotor. Intake fluid pressure is applied to spaced defined between each of the grooves and the bottom of the corresponding vanes during suction strokes through a first arcuate groove. A second arcuate groove is formed in an inner surface of the side housings at a position corresponding to the spaces during compression strokes. A pressure discharge passage connected to the arcuate groove and an outlet port is provided and a check valve is provided in the pressure discharge passage.
