A rotary compressor includes: a compressing unit that includes an annular cylinder, an end plate which has a bearing unit and a discharge valve unit and closes an end portion of the cylinder, an annular piston which is fit in an eccentric portion of a rotation shaft supported in the bearing unit, performs an orbital motion inside the cylinder along a cylinder inner wall of the cylinder, and forms an operation chamber together with the cylinder inner wall, and a vane which protrudes from the inside of a vane groove of the cylinder to the inside of the operation chamber, comes into contact with the annular piston, and partitions the operation chamber into an inlet chamber and a compression chamber. The vane is formed of steel and has a diamond-like carbon layer formed on a sliding surface with respect to the annular piston. The annular piston is formed of Ni-Cr-Mo cast iron to which 0.15 wt% to 0.45 wt% of phosphorus is added, or is formed of cast iron or steel and has an iron nitride layer formed on an outer circumferential surface thereof.