PURPOSE: To produce a stamper for a magneto-optical disk having excellent performance by using a semiconductor single crystal for a substrate for pattern transfer and forming fine physical ruggedness by etching in a part of the substrate for pattern transfer.

CONSTITUTION: The Si single crystal, etc., are formed into a disk shape to form the substrate. One surface of the substrate is precisely polished to a specular surface shape and a resist 6 is applied to the part 4 corresponding to the information recording region of the disk. The region 5 on the inner peripheral side where the substrate 3 is exposed is etched to a prescribed shape. The resist applied to the information recording region part 4 is thereafter peeled to form the substrate 3. The resist 7 is applied on this part 4. Exposing traces to constitute the base for pits or grooves are formed on the resist 7 and are hard baked after development. A conductive film is formed by plating, sputtering, etc., on the substrate 3, by which a master disk for electrocasting is formed. An Ni, etc., is electrocast to the master disk. An electrocast body and the master disk are then peeled and the peeled surface is polished. A circular aperture 9 is blanked in the central part, by which the stamper 1 is produced.