Disclosed is a compressor. A lubrication surface, which has the same curvature as an inner circumferential surface curvature of a cylinder and which has a predetermined circumference length, is formed on an outer circumferential surface of a roller contacting an inner circumferential surface of the cylinder. With such a configuration, since the outer circumferential surface of the roller contacting the inner circumferential surface of the cylinder come in surface-contact with each other, an oil film is formed between the roller and the cylinder with a wide area. This can reduce a frictional loss.