There is provided a compressor provided with a motor rotor capable of suppressing a decrease in oil separation efficiency and avoiding a decrease in motor efficiency. A motor rotor (10) includes a substantially cylindrical rotor laminated steel plate including a permanent magnet therein. The rotor laminated steel plate includes a plurality of refrigerant gas holes (18) passing therethrough in the axial direction and a plurality of rivet holes (20) arranged in the circumferential direction and passing therethrough in the axial direction. At least one of the rivet holes (20) is used as a positioning hole (20b) to insert a positioning pin for positioning in the rotation direction at the time of rotor magnetization.