A compressor, characterized in that a steel is used as the base material for the other sliding material vane 10 and nitrided, a CrN or DLC film is formed on the surface by PVD treatment, and a Ni-Cr-Mo cast iron is used for the other corresponding sliding material piston 9. It is possible in such a configuration to suppress the temperature rise by sliding friction of the sliding materials, such as the vane tip region 10a and the peripheral region of piston 9 that are vigorously slid, relax decomposition of the refrigerant, and suppress corrosion by hydrogen fluoride generated in reaction with water and oxygen, and thus to provide a compressor higher in reliability.