at least two lamps, each of the lamps including:

a lamp body including a fluorescent layer formed on an inner surface of the lamp body and a discharge gas disposed in the lamp body;

a first electrode for providing the lamp body with a first discharge voltage; and

a second electrode for providing the lamp body with a second discharge voltage;

a first lamp holder having a pipe-shape, a first end portion of the lamp being inserted into the pipe-shape to be fastened to the first lamp holder;

a first board having a flat plate shape and being coupled to first electrodes of the lamps to provide the first electrodes with the first discharge voltage, the first board including:

a first insulated body having a first inward surface that makes contact with the first lamp holder and a first outward surface that is opposite to the first inward surface;

a first conductive pattern formed on the first outward surface of the first insulated body; and

at least two first through-holes formed on the first insulated body and each of the first through-holes receiving the first electrode of each of the lamps, the first electrode extending through the first through-hole to the first outward surface of the first insulated body and being electrically connected to the first conductive pattern;

a first connector installed on the first board to electrically connect the first electrodes that are coupled to the first board to an inverter that generates the first discharge voltage, the first connector being disposed between the at least two first through-holes; and

a first terminal removably coupled to the first connector to receive the first discharge voltage from the inverter and provide the first discharge voltage to the first connector, the first terminal is configured to facilitate disassembly and reassembly with a coupling portion of the first connector to provide electrical connection therebetween.