A fuel cell separator includes a first separator plate and a second separator plate for an anode or a cathode. The first separator plate and the second separator plate are adjacent to each other for assembly in a fuel cell stack. The fuel cell separator further includes a first protrusion formed at an edge portion of the first separator plate and protruding toward the second separator plate arranged facing the first separator plate and a second protrusion formed at an edge portion of the second separator plate and protruding toward the first separator plate arranged facing the second separator plate. With the first separator plate and the second separator plate adjacent to each other, since opposing side surfaces of the first protrusion and the second protrusion push each other, assembly positions of the first separator plate and the second separator plate are regulated.