A refrigerant compressor comprises an electric element; a compression element; and a sealed container; wherein the compression element includes: a crankpin; a piston pin; and a connecting rod having a large hole portion into which the crankpin is inserted, a small hole portion in which the piston pin is rotatably disposed, and a coupling rod portion; wherein an oil guide hole is provided in the coupling rod portion of the connecting rod such that the large hole portion and the small hole portion are communicated with each other via the oil guide hole; a circular first groove is provided on an outer peripheral surface of the piston pin such that the first groove communicates with the oil guide hole; and a second groove extending in a center axis direction of the piston pin is provided in a first region of the small hole portion of the connecting rod.