In a method of producing a resin frame member for a fuel cell, a processing die is used. The method includes a processing step of moving an upper die toward a lower die to thereby form an inclined surface on each of side parts of a resin film. In the processing step, shearing is performed while maintaining a predetermined clearance between the lower processing section and the upper processing section and in a state where each of the side parts is at least partially positioned at a cutout so that each of the side parts is inclined downward toward the inside. The cutout is formed by cutting off an edge part of a placement surface that is positioned on the lower processing section side.