To provide a disk substrate, in which ski jumps or burrs generated on the resin disk substrate are removed, a manufacturing method and a manufacturing device therefor.

The manufacturing device for the disk substrate is provided with a pair of metallic molds 2, 3 for press, which applies the press treatment to at least the outer circumferential end part of the resin disk substrate 20 by interposing the resin disk substrate 20 from both principal plane sides, and a cylinder 7, which keeps a pair of the metallic molds 2, 3 for press in a tightened state by driving the metallic mold 3 for press and pressing the mold against the metallic mold 2 for press at the time of the press treatment. Then, a pair of the metallic molds 2, 3 for press are made to a notched form at areas corresponding to the outer circumferential end part of the disk substrate 20. Consequently, the outer circumferential end part is press formed, thereby the disk substrate, in which burrs or ski-jumps are removed, are obtd.