Method of manufacturing a polymer electrolyte fuel cell material

A polymer electrolyte fuel cell material comprising a plate material (41) composed of an Fe-base alloy, Ni-base alloy, Ti or Ti-base alloy, and a cover film (44a, 44b) of a noble metal covering the surface (42, 43).The cover film (44a, 44b) on the plate material (41) has a surface roughness as expressed in Rof 1.5 µm or less.