A reciprocating compressor has a plurality of compressor stages each compressing a working gas by combining a cylinder and a plunger, and its discharge pressure exceeds 40 MPa. The compressor stage has a packing seal which seals a shaft of the plunger, and oil pouring means which pours a lubricating oil to the packing seal. A filter removes the lubricating oil poured by the oil pouring means from the working gas. In the filter, a first element using micro glass fiber and a second element using functional activated carbon are coaxially mounted. These two elements are included together in a pressure container. According to the above described construction, in the compressor at a high pressure exceeding 40 MPa, quality of the discharge gas can be kept and the compressor can be made compact.