To illuminate a body to be illuminated from under by providing a light diffusing layer, a light guide layer for guiding the incident light from the end surface side to the flat side, a reflecting layer opposed to the light diffusing layer with the light guide layer between, and a light source on the light guide layer end surface.

A dimming scattering surface is provided on the surface of a transparent resin plate such as acrylic resin to form a light guide layer 3. The light emitted from a light source 6 is incident on the center end surface of the light guide layer 3, repeatedly totally reflected within the layer, scattered by the dimming scattering surface in the course leaving the light source 6, and emitted from the layer surface to a light diffusing layer 2. The light emitted to the reflecting layer 4 side is reflected by the reflecting layer 4, vertically transmitted by the light guide layer 3, and emitted to the light diffusing layer 2. The light emitted to the light diffusing layer 2 is diffused and uniformed, transmitted by a cover layer 5 for protecting the inner part from impact, penetration of water or the like, and emitted to the outside of the device. Accordingly, the light can be emitted upward from the whole upper surface of a lighting system 1. The light source 6 consists of a light quantity regulating slidac 11 and freely regulates the quantity of light.