Abstract: An optical disk includes a disk substrate made of synthetic resins and an elastic/non-elastic film for label printing. The disk substrate has a chucking central aperture, and the peripheral portion of the chucking central portion constitutes a clamping area. The film is fixed on an upper surface of the disk substrate so as to cover the chucking central aperture. In case of the elastic film, at least a portion of the film corresponding to the chucking central aperture expands/contracts in accordance with the movement of a disk chuck into/out of the chucking central aperture. On the other hand, in case of the non-elastic film, cuts are made in a portion corresponding to the chucking central aperture, whereby the cut portion of the film opens/closes in accordance with the movement of a disk chuck into/out of the chucking central aperture.