Disclosed herein is a lighting device using a cold cathode fluorescent lamp (CCFL), which has reduced size and volume and concentrates light from the CCFL, thus enhancing its luminance. The lighting device includes a casing which is open on a surface thereof, thus having an open part, with an ON/OFF switch button which protrudes through a sidewall of the casing and is used to turn on or off the lighting device. A reflective plate is inserted into the casing through the open part, with a circuit board provided on a predetermined position of the reflective plate. A CCFL is inserted into the reflective plate and electrically connected to the circuit board with a cover assembled with the casing and receiving the CCFL between the casing and the cover. A socket is assembled with each end of the casing that supports both the CCFL and the cover, and is electrically connected to the circuit board.