It is an object of the present invention to provide a process for manufacturing a high-density optical disk having excellent optical properties by suppressing the production of a cloud caused by a release failure and preventing the deterioration of hue and light transmittance.The present invention is a process for manufacturing a high-density optical disk, comprising the steps of: (1) preparing a resin composition comprising an aromatic polycarbonate resin and a predetermined amount of monoglyceride behenate; (2) injecting molding the resin composition to obtain a substrate; and (3) forming an information recording/reproduction layer on the substrate, wherein the aromatic polycarbonate resin has a sodium metal content of 0.0005 to 0.05 ppm and a viscosity average molecular weight of 10,000 to 20,000, and the monoglyceride behenate has a sodium metal content of 1 ppm or less.