An identification medium which ca be printed freely as needed, cannot be easily falsified, appears singularly thereby to be easily authenticated, and can be produced inexpensively. A cholesteric liquid crystal layer (10) or a multilayer thin film (5) composed of multiple optical thin films having different refractive indices and a braking-type printing recording layer are formed in a multilayer structure. Therefore the identification medium has such a singular optical property that the displayed colors of the characters, symbols, patterns, and designs printed by, e.g., a thermal printer vary depending on the viewing angle. An identification method using such an optical property is also provided.