To provide an optical disk using a thin injection molded substrate which can be used ton the handy movie camera of small mass eccentricity, and a laminated optical disk by using the thin injection molded substrate.

This laminated optical disk includes a single-plate injection molded substrate having a thickness of 0.8 mm or less, an outer diameter of which is 100 mm or less, and mass eccentricity of which is 0.1 g/cm.