PURPOSE: To shorten the production time by irradiating a composition forwarded with the revolution of an embossing roll with light, curing the composition, punching the composition to a specified shape, evaporating a metal on the irregular surface side and lastly forming a protective layer onto an evaporating surface.

CONSTITUTION: An embossing roll 1 on which an information bit is marked is turned in the clockwise direction while being sucked by a vacuum pump, and a photosensitive composition is applied. The photosensitive composition is irradiated with light by an ultraviolet irradiator 7 on the embossing roll 1, and a sheet 8, the roll side of which is cured and the top face side of which is not cured, is formed. The sheet is forwarded to a joining section with a roll 10 on which a metallic belt 9 is stretched, and sent while being abutted against the metallic belt 9 from the joining section, and the abutting side is interrupted from air. The sheet 8 is irradiated with light by an ultraviolet irradiator 11 again during abutting, the metallic belt 9 abutting side is cured, and an information bit is shaped on the heavy line side of the sheet 8. The sheet is cured, and peeled from the metallic belt 9, and an optical disk is completed through the processes of punching, metallic evaporation and a protective layer cover.