PURPOSE: To shorten a time required for a peeling process by forming a metallic thin film only on a pre-group forming area on an optical disk.

CONSTITUTION: An optical master disk 23a is manufactured by forming a Cr metallic film 12 on a glass plate 11 at a range where a pre-group is formed as a bed metallic film, and forming a groove in spiral shape on an Au metallic film 13 after the Au metallic film 13 is formed on the bed metallic film. Next, resin 15 for ultraviolet ray curing is applied to the optical master disk 23a, and it is pressed with a substrate 16 made of glass, and the resin 15 is spread entirely between the substrate 16 and the optical master disk 23a. Next, curing is performed by irradiating the resin 15 with ultraviolet ray from the upper side of the substrate 16 by an ultraviolet ray lamp 17, and the substrate 16 is peeled from the optical master disk by using a peeling jig 18, then, an optical disk substrate is manufactured. In such a manner, the adhesive area of the metallic film with the resin for ultraviolet ray curing can be reduced, and a peeling work can be performed in a short time.