PURPOSE: To obtain an excellent magnetic disk having high hardness, corrosion resistance, and a heat resistant substrate by coating, drying and baking of an org. metallic compd., etc. on the surface of a base material consisting of sintered pulverous powder of Al2O3, etc. to form a thin continuous film and providing successively a magnetic film, protective film or lubricating film on the thin continuous film.

CONSTITUTION: Pulverous powder of Al2O3, SiO2, MgO, TiO2, TiC, etc. and a binder as water of alcohol are cast into a mold and are sintered under the pressure, by which the base material 1 for the disk is manufactured. The org. metal 2 as expressed by Si(OR)4, M(OR)n, where M is Al, Ti, Fe, Cr, etc. and R is alkyl, is spin-coated on the surface of the material 1. The coating is heated in air or gaseous N2 to form the thin continuous film 3 consisting of metallic oxide or nitride, by which the smooth and dense film having high hardness is obtd. A magnetic layer 4 is formed on the film 3 without the need for a polishing stage and if necessary, the protective film and lubricating film 5 are successively formed thereon. The disk having the excellent magnetic characteristic, heat resistance, corrosion resistance, etc. and excellent durability is thus obtd.