PURPOSE: To provide a method and a device for reproducing an optical disk used exclusively for reproducing.

CONSTITUTION: A process for production of a source disk 17' and a process where information of the source disk is optically copied to a target disk 52 are included. The source disk has a transparent substrate 18 and a prescribed opaque recording layer 20 applied on this substrate 18, and recording holes 21 through which light is transmitted are formed in the opaque recording layer, and information is stored by arrangement of these recording holes. The target disk has a photochromic recording layer where the coefficient of light absorption before copy and that after copy are different. The method for producing this optical disk only for reproducing uses an optical recorder, which optically forms recording holes of the source disk, and a copying device which optically copies information from the source disk to the target disk. Thus, the optical disks used exclusively for reproducing are inexpensively mass-produced in a short time.