PURPOSE: To raise yield of a photomask of a metallic substrate, by coating a positive type photoresist film on a transparent substrate coated with a metallic film having pinholes, irradiating the reverse side of the transparent substrate with light, and, after removing the exposed resist film, vapor depositing the second metallic film.

CONSTITUTION: To correct a transparent substrate coated with a metallic film having pinholes of the metallic substrate of a photomask or the like for manufacturing integrated circuits, a photoresist film 7 is formed on the whole surface of a metallic pattern 2 having pinholes 3 on the substrate 1. Then, the reverse side is exposed to light 8, the exposed parts 3 of the resist film 7 are removed by development, and the second metallic film 2 is formed by the vapor deposition method or the like. The remaining film 7 and the second metallic film 2 left are removed to obtain the metallic pattern with the pinholes 3 corrected, thus permitting yield of the metallic substrate for a mask or the like to be enhanced.