A lamp holding unit includes a coupling terminal and a main body. The coupling terminal includes a coupling plate extended in a direction crossing a longitudinal direction of a lamp. The coupling plate has a cutout portion to receive a lead line of the lamp so that the cutout portion of the coupling plate making contact with the lead line. The main body is coupled with the coupling terminal and guiding the lamp. Therefore, an electrical connection between the lamp holding unit and the lead line of the lamp is stabilized, so that noise or spark caused by mal-connection is prevented.