To provide an optical disk metallic mold and an optical disk substrate forming method, wherein one temperature controller is provided for one mirror finished surface, proper flow path designing is carried out inexpensively according to substrate specifications without changing a mirror finished member, and the contraction of a formed substrate is uniform in a diameter direction.

Flow paths 5a and 16a for controlling the temperature of the mirror finished member of a metallic mold 2 are formed by at least providing recessed and projected parts in a cap member adjacent to the mirror finished member. By changing the sectional area of the flow path in a diameter direction, a resin cooling speed is controlled in the diameter direction even in the temperature control flow path having an entrance and an exits, one each, and the contraction amount of resin is made uniform.