A rotary compressor is provided with a rotary sleeve mounted in a center housing for rotation with a plurality of vanes movable in a rotor which is eccentrically disposed in the rotary sleeve. An air-bearing room is defined between the outer periphery of the rotary sleeve and the inner periphery of the center housing and supplied with air through an inlet internally connected to the discharge chamber or compression working space under the maximum pressure. A multiplicity of air-accumulating grooves are formed in either or both in the outer periphery of the rotary sleeve and the inner periphery of the center housing. The air-accumulating groove is composed of a suction portion gradually inclined from the peripheral direction and a compression portion sharply inclined from or perpendicular to the peripheral direction. The inlet is peripherally alined with the suction portion of each air-accumulating groove, so that air is guided to the suction portion and compressed in the compression portion of the groove to increase the bearing effect of the air-bearing room.
