PURPOSE: To form a base plate, which can be produced at low cost in a short time while saving labor for producing the disk-shaped optical recording carrier of plastic material of CD or LD (video disk), for example, from the plastic material in place of conventional glass.

CONSTITUTION: Concerning the base plate to be used for producing a metal die to be used for producing the disk-shaped optical recording carrier of plastic materials, this base plate is provided by using the plastic materials. The base plate has a property of absorbing laser write light and transmitting laser measured light from an order meter as one condition. The base plate is worked by performing the injection molding of plastic material such as polyetherimide, after this injection molding, static charges are removed from the base plate and further, it is preferable to perform high-grade grinding.