A backlight device includes a first substrate having optical transparency and having first and second surfaces opposite to each other. An LED thin-film is fixed to the first surface of the first substrate. An anode electrode and a cathode electrode are formed on the LED thin-film. An anode driver IC and a cathode driver IC are provided for driving the LED thin-film to emit light. An anode wiring and a cathode wiring are provided on the first surface of the first substrate. A second substrate has optical transparency, and has first and second surfaces opposite to each other. The second surface of the second substrate faces the first surface of the first substrate. A reflection film is provided on the first surface of the second substrate. A light diffusion plate is provided so as to face the second surface of the first substrate and has a function to diffuse incident light.