Disclosed is a liquid crystal display device for realizing a large surface display screen. The liquid crystal display device has a light guiding plate formed at least at one portion of a light source for converting a light generated from the light source into a planar light having a uniform luminance and advancing in a first direction. Light control member composed of a semitransparent or an opaque material is formed between the light guiding plate and the light source for preventing the light from directly advancing in the first direction. With improvement of the structure of a light supply unit, the liquid crystal display device can have much simplified construction and be easily manufactured. Also, the light guiding plate can have greatly reduced thickness by forming the light control member, and the liquid crystal display device can have a large surface display screen because a luminance of an image displayed on the screen is uniformly maintained by means of uniformly maintaining the luminance of light emitted the light source.