An optical disk comprising a plastic disk body having fluorescent coloring material dispersed therein. Pits representing stored data are formed on a first main surface of the plastic disk body, a reflecting layer is formed over the first main surface having the pits and a protecting layer is formed over the reflecting layer. When the optical disk is subjected to an external light, the fluorescent coloring material emits a radiation of a fluorescent light of a particular color, which can be seen at the opposite, second main surface and the outer circumferential surface of the optical disk. The optical disk can be also subjected to a laser beam for regenerating data stored in the optical disk.