The present invention aims at increasing service life of an inner circumferential stamper holder in a die for molding disc substrates that is used when the disc substrates are injection molded. To that end, in the die for molding the disc substrates in which a stamper 3 is supported by at least one of a stationary die 6 and a movable die 1, an abrasion resistant treatment is applied to at least a portion, which abuts against a side surface 3a of a center opening of the stamper 3, of an outer circumferential surface 4a of the inner circumferential stamper holder 4 supporting the stamper 3.