To solve the problem that the positions and shapes of light emitting elements are heretofore dimly visually recognized as there is the various density in the light transmitted through a light transparent cover.

Transparent resin plates 21 and 22 (light transparent covers) are formed with plural grooves 21b and 22b formed to an approximately semicircular shape at the perpendicular section based on the direction where the grooves are formed in approximately parallel and these plates are superposed on each other in such a manner that the directions formed with the grooves 21b and 22b do not overlap each other. The directions where the light is diffused is different by the respective transparent resin plates 21 and 22 and therefore the light from the light emitting elements diffuses intricately and the positions and shapes of the light emitting elements are no longer visually recognized, by which the aesthetic appearance is improved.