PURPOSE: To obtain a master disk capable of being read by the reader of an optical disk to be usable many times in order to produce a new mold without being accompanied by any post-treatment.

CONSTITUTION: A material layer 9 is applied to a substrate 1 and a photosensitive resin layer 2 is subsequently applied to the material layer 9 to be irradiated with laser beam 3. A microcup 6 is formed excepting the exposed area 4 of the photosensitive resin layer 2 to express data to be reproduced. This data is transferred to the uncoated area 7 of the material layer 9 and the unexposed area 5 of the photosensitive resin layer 2 is removed to obtain a master disk. Finally, the substrate 1 is detached to obtain a press mold 10.