PURPOSE: To provide the lighting system which increases an area ratio of the light emission face to the surface of a light transmission plate and reduces the unevenness of luminance.

CONSTITUTION: A light source 1 is placed to face an incidence face 2i set on the peripheral surface of a light transmission plate 2 like a plane plate, and a diffuse transmission layer 3 is provided on the surface of the light transmission plate 2, and the surface of the diffuse transmission layer 3 is a light emission face 2r which emits light like a surface. A reflection layer 4 is provided on the rear face of the light transmission plate 2. The reflection layer 4 consists of many reflection patterns, which are printed on the rear face of the light transmission plate 2 and have a diffuse reflection property, and a reflection plate which is laminated on the rear face of the light transmission plate 2 with reflection patterns between them and has a specular surface. Distance L1 between the edge on the side of the incidence face 2i of the diffuse transmission layer 3 and the incidence face 2i and a distance L2 between the edge on the side of the incidence face 2i of the diffuse transmission layer 3 and the incidence face 2i are set to satisfy 3n.t>L1>L2 where (t) and (n) are thickness dimensions and the refractive index of the light transmission plate 2 respectively.