Abstract: An anticorrosive treatment method for a separator of a molten carbonate fuel cell is provided. As conventional anticorrosive treatment methods for a wet-seal area in an separator, there are a molten aluminium coating method, a physical vapor deposition method, a slurry coating method, a spray coating method, a pack cementation method and a vacuum evaporation method. Defects due to high temperature thermal treatment corrodes even stainless steel base materials to thus shorten the lifetime of the fuel cell. Further, to sufficiently assure an anticorrosive capability of the separator wet-seal area, a coating ratio should be heightened finally, which makes fabrication of the large-area separator difficult, and manufacturing costs high. To solve the conventional problems, nickel and aluminium are coated in turn on a base material of stainless steel or an thin aluminium film is coated or bonded thereon to then perform diffusion process, which simplifies a manufacturing process and lowers a manufacturing cost.