Abstract: A method of manufacturing a metal separator for a fuel cell includes molding first and second plates such that each plate has at least one concave portion and at least one convex portion; applying a sealant to at least one of the plates; placing the plates such that the concave portions of each plate are opposite the convex portions of the other plate, and the ends of the second plate protrude beyond the ends of the first plate; and seaming the ends of the first plate to the ends of the second plate. The seaming may include bending the ends of the plates at right angles with a conical roller, bending the ends of the second plate to surround the ends of the first plate with the conical roller, and bending the ends of the plates at right angles with a cylindrical roller.