A method for producing a separator for a fuel cell including, first, mixing carbon particles with thermoplastic resin particles to produce mixed particles, and kneading the mixed particles into pellets. Second, the pellets are extruded and formed into a sheet-form base material. Third, the sheet-form base material is grooved by rolling with a roller having a pattern on a peripheral surface thereof. The pattern on the roller is transferred on the separator to have a predetermined groove pattern.