The present invention provides a light-weighted backlight capable of ensuring a sufficient light quantity at a low cost. A backlight is arranged below a liquid crystal panel. A light source is arranged in the vertical direction with respect to a screen of the liquid crystal panel so that light from the light source is directed toward the liquid crystal panel by a reflector. Due to such a constitution, the reflector can also function as a back lid of the backlight. Further, the reflector plays a role of directing the light from the light source toward the liquid crystal panel and hence, a light guide plate can be omitted. Due to such a constitution, the present invention can realize the reduction of weight and cost of the backlight or the liquid crystal display panel.