To provide a liquid crystal display device having excellent uniformity in the brightness so that the performance of displays of liquid crystal can be increased.A liquid crystal display device is provided with: a support member: a heat releasing member provided on this support member; a light guiding plate 121 provided on a rear surface of a liquid crystal panel; and a light source module 124 which is thermally secured to the heat releasing member so as to face an entrance surface 121a formed on one or two sides in the direction of the length of the light guiding plate 121 and has a light source for emitting a light beam toward the entrance surface 121a, wherein the light source is covered with a lens 124c in the light source module 124, and the distance D between the lens 124c and the entrance surface 121a when the light source module 124 is not driven is set within a certain range.