PURPOSE: To decrease the number of light sources that are radiated uniformly so as to reduce the cost by making a constitution with polished surfaces, and rough surfaces formed at surfaces other than the polished surfaces of a light permeation member thereby allowing light from light sources to be diffused by means of rough surfaces.

CONSTITUTION: A printed board 5 having a plurality of LEDs 4 that are light sources, is fixed at the frame 3 of an opening portion 2. There is provided a light transmission member 8 at which an engaging portion 6 engaged with the opening portion 2 and a surrounding portion 7 that is bent downward from the portion 6 back side and surrounds LEDs 4, are integrally formed out of a light transmission material. Also, polished surfaces 9, 10 are formed at the surfaces of the portion 6 exposed to the outside through portion 2, and polished surfaces 11 are formed at the surfaces opposite to LEDs 4 at the portion 7. Rough surfaces 12 which diffuse light are formed by crimping or the like at one surface of the member 8, that is, a back surface opposite to the surface 9, a side surface opposite to the surface 10, an upper surface and the like opposite to the surfaces 11.