A reciprocating compressor includes: a low-pressure stage compression part for compressing low-pressure working gas supplied from a supply source; two high-pressure stage compression parts for compressing the working gas compressed by the low-pressure stage compression part at two stages; and a crank mechanism for driving the low-pressure stage compression part and the high-pressure stage compression parts. The two high-pressure stage compression parts each have a plunger and a cylinder and are arranged on both sides of the crank mechanism in such a way as to extend coaxially opposite to each other. The low-pressure stage compression part has a piston and a cylinder and is located in the middle of the two high-pressure stage compression parts. The crank mechanism, the low-pressure stage compression part, and the two high-pressure stage compression parts are substantially located in the same plane.