Abstract: A multi-vane type compressor formed with vane back pressure spaces having introduced thereinto a suction gas pressure in the suction and compression strokes and a discharge gas pressure in the discharge stroke. The compressor includes supply grooves for introducing the discharge gas pressure into the vane back pressure spaces, which are each split into a trailing side portion and a leading side portion. Each leading side portion for coping with the terminating stage of the discharge stroke is exposed to the discharge gas pressure via a passageway offering large resistance to the flow of fluid, to throttle the gas forced out of the vane back pressure spaces as the vanes are forced into vane grooves to thereby raise the vane back pressure. This is conducive to prevention of the jumping action of the vanes, and wear of the tips of the vanes and to minimization of vibration and noise.