PURPOSE: To obtain a high-quality underlying layer with which the number of defect is small by converting metal zinc to a gaseous phase and sticking metal zinc onto a nonmagnetic substrate, then providing a nickel-phosphorus film formed by a plating method on the zinc layer as a nonmagnetic metallic film.

CONSTITUTION: The plating film formed after the zinc particles to constitute the nuclei for film growth in a plating process are stuck in the following manner is used as the nickel-phosphorus film to be used as the underlying layer of a magnetic disk. Namely, the metal zinc is converted to atoms, ions, radicals, etc., by heating in a vacuum, etc., which are then stuck onto the substrate and the nickel-phosphorus film is formed by the plating method. The uniform growth of the nickel-phosphorus film on the substrate surface is thereby enabled and since the formed nickel-phosphorus film has the smaller number of defects, the magnetic disk produced by forming an intermediate film, magnetic film and protective film with the above-mentioned film as the underlying layer is the high-quality disk having less recording errors.