A disk media has an IC chip which is mounted thereon at a boundary peripheral portion of a metal film layer formation region with respect to a metal film layer non-formation region. The IC chip is mounted on a top surface of the metal film layer. An “L”-shaped slit is formed in the metal film layer at the mount position of the IC chip while causing signal input/output electrodes of IC chip to be connected to portions of the metal film layer which are placed on the opposite sides of the slit. With such an arrangement, it is possible to use the metal film layer as an antenna of IC chip while enabling the impedance of IC chip to match the impedance of the antenna formed by the metal film layer.