In a printed board having a land as an electrode, a colored thermoplastic resin film is arranged on a land forming surface of a thermoplastic resin member so as to set a difference in light reflectivity between the land and the colored thermoplastic resin film, to be greater than that between the land and the thermoplastic resin member. An opening portion is provided in the colored thermoplastic resin film so that at least a part of the land is exposed from the opening portion. Because the colored thermoplastic resin film is positioned on the circumference portion of the opening portion, the difference in light reflectivity of the land with respect to its circumference portion can be effectively increased. As a result, a recognition ratio of the land can be effectively improved.