Abstract: To produce a fuel-cell separator formed with a plurality of protuberances on its base plate, a lower die is assembled by stacking a plate in intimate contact with a lower-die base with a mirror-finished surface, the plate having a plurality of through holes extended therethrough and a uniform thickness. A side frame is stacked on the lower die to charge a molding material therein. Then, the material is heated and compressed with an upper die to mold an article with protuberances having a constant height and a constant flatness at their top surfaces.