A backlight unit of a hybrid structure is disclosed, to improve heat-sink efficiency, that includes a plurality of fluorescent lamps oriented in one direction inside a cover bottom; a metal PCB attached to an inner surface of the cover bottom; a plurality of LED lamps each positioned between the fluorescent lamps and on the metal PCB; a hole in a portion of the cover bottom that exposes a rear surface of the metal PCB; and a heat-sink plate directly attached to the metal PCB through the hole in the cover bottom.
