Sheet press molding method and method of manufacturing fuel cell separator

A method of manufacturing a fuel cell separator, comprising:

• a process of forming a fuel cell separator having a flow channel recessed portion, to which a recess and protrusion pattern is transferred, by pressurizing a sheetshaped material including a resin composition and 80 mass% to 98 mass% of a carbonaceous material using a pair of molds, at least one of which has a predetermined recess and protrusion pattern composed of recessed portions and protruding portions, wherein
• the pair of molds have a first mold and a second mold,
• the first mold includes a channel pattern having one or more protruding portions disposed on a position corresponding to the flow channels, a dummy pattern having one or more dummy protruding portions, and one or more recessed portions which is formed between the protruding portions of the channel pattern, the dummy protruding portions, and the side surfaces of the inside of the first mold,
• the dummy protruding portions are separated from the protruding portions of the channel pattern by the recessed portions, and
• the total volume of the protruding portions of the channel pattern and the dummy protruding portions is same as the total volume of the recessed portions, wherein the total volume of the recessed portions refers to the volume of the recessed portions between an imaginary surface along the top surface of the first mold and the bottom of the recessed portions.