PURPOSE: To prevent a fluorescent tube from being broken in the case of exerting force on the vicinity of the center part of a backlight in a vertical direction to an irradiating surface by providing a pedestal for supporting the center part of the fluorescent tube in the center part of a reflector.

CONSTITUTION: A pedestal 6 for supporting the center part of a fluorescent tube 2 being a light source is provided in addition to a lamp supporting base 3 for supporting both ends of the fluorescent tube 2 on a reflector 1 which forms the external frame of the backlight and which reflects the light from the light source to the irradiating surface side. By making a mechanism for fixing and supporting the fluorescent tube 2 have structure that the tube is supported not only by two points at both ends of the tube but also by the center part of the tube, the fluorescent tube 2 is prevented from being broken by using a small-diameter fluorescent tube because of thinning the backlight, and the backlight having high reliability is supplied.