Each of plural light source units is formed by combining a light source formed of plural light emitting elements mounted on a wiring substrate with a light guide plate having a side surface serving as a light incident surface. The wiring substrate is attached to the chassis such that the light output surface of the light emitting element is perpendicular to the light emitting element mount surface of the wiring substrate. The wiring patterns each with the larger width than that of the electrode are formed on both upper and back surfaces of the substrate at the portion to which the power feeding electrode of the light emitting element is soldered. They are connected via the through holes which are arranged in plural rows around the electrode.