PURPOSE: To rapidly cure an adhesive consisting of two-pack type photosetting resins and to improve productivity by tightly sticking the joint surfaces of transparent substrates by using this adhesive, thereby forming the optical disk.

CONSTITUTION: Information recording layers 3 are formed on the transparent substrates 2 and the joint surfaces 1, 1 are stuck to each other by using the adhesive 4. The adhesive 4 consists of a compsn. contg. components a to f. The component a is an elastomer component or one kind or <1 kinds of oligomer components having at least one of polymerizable ethylenic double bonds within the molecule; b is a monomer having at least one of carboxyl groups in the molecule; c is phenyl(meth)acylate; d is an org. peroxide; e is an inorg. or org. metal slat; f is a photopolymn. intiator. The content of the component c is specified to 10 to 70wt.% by the total resin weight. As a result, the optical disk 5 having excellent cryogenic cycle resistance and moisture resistance and high reliability is obtd.