A compressor is provided in which an outer circumferential side cross-sectional area of a vane slot is formed smaller than an inner circumferential side cross-sectional area thereof to decrease an area receiving a force in a roller direction by a vane to reduce a contact force between the roller and the vane, and a gas accommodation portion selectively forming a suction pressure and an intermediate pressure is formed between the vane and the vane slot to control the contact force. A contact surface of the vane facing the roller is formed at a side of a compression chamber to reduce the contact force, and a space forming a discharge pressure is formed at at least either one side of a side surface of the vane and a cylinder to decrease a side directional reaction force applied to the vane, thereby reducing a friction between the vane and the cylinder.