An optical disk having a warp preventive film for preventing the warp of the substrate which does not exfoliate for a long period by forming the warp preventive film on a textured area on the substrate surface with a minute embossment, and a method of manufacturing the optical disk by controlling the plasma etching condition for forming a textured area for reinforcing the bonding force of the warp preventive film on the substrate surface, so that the warp preventive film being bonded after forming the textured area may not exfoliate for a long period.