An object of the present invention is to provide a liquid-crystal display device which includes a diffuser board that does not produce striped mura on the surface of a liquid crystal panel even if point light sources are used as light sources of a backlight.A backlight apparatus 103 is provided with a diffuser board 103b having diffusion portions 103b1. At each of the diffusion portions 103b1, the light L emitted by a LED module 104 included in a light source unit 103a is reflected by prism patterns P and diffused around the LED module 104. Then, the diffused light is reflected again by a reflecting surface formed on the inner surface of a housing 103c and emitted from the backlight apparatus 103, thereby achieving illuminating light without mura.