A first lamp electrode supporter includes a first terminal having a first lamp electrode fixing hole through which a lamp electrode is inserted, and a second terminal connected to an inverter connector. A second lamp electrode supporter is disposed opposite to the first lamp electrode supporter. The second lamp electrode supporter has a second lamp electrode fixing hole through which the lamp electrode is inserted. A peripheral portion corresponding to the second lamp electrode fixing hole is formed closely to the first lamp electrode supporter. A connecting part connects the first lamp electrode supporter and the second lamp electrode supporter. An elastic guide part is extended from the connecting part to a spacing between the first and second lamp electrode supporters. The elastic guide part supports the lamp electrode when the lamp electrode contacts the first and second lamp electrode fixing holes.