To provide an illumination unit which improves the assembling characteristic of lead wires connected to a light source and a liquid crystal display device having the same.

The illumination unit UT which has the light source 2, a light transmission plate 1 for guiding the light from the light source 2 and a metallic casing 9 arranged below the light transmission plate 1 and in its lateral direction and is formed with a display area above the light transmission plate 1 is arranged with the leas wires 7 connected to the light source 2 between the flank of the light transmission plate 1 and the casing 9 and is reduced in the disengagement of the lead wires 7 by the projection to the inner side disposed on the flank of the casing 9.