PURPOSE: A backlight unit is provided to improve the efficiency of light by efficiently supplying light which is generated in light source to a liquid crystal panel and to form the vertical width of a light guide plate and a light source. CONSTITUTION: A backlight unit includes a light source(118) and a light guide plate(106). The light source examines the light on the liquid crystal panel. The light guide plate changes the light which is income from the light source into the surface light source. The light guide plate is adhered with the light source. A light blocking member is attached in order to block light in the upper side of the index matching material.
