A light source device includes a light emitting body, a pair of main electrodes and a pair of sub electrodes. The light emitting body includes discharge spaces disposed substantially parallel to each other. The main electrodes are disposed at opposite end portions of the light emitting body, respectively. The main electrodes induce an electrical discharge of a gas in the discharge spaces between the main electrodes. The sub electrodes are disposed between the main electrodes. The sub electrodes induce an electrical discharge of a gas in the discharge spaces between the sub electrodes. Resultantly, power consumption is reduced and uniformity of luminance is enhanced. Therefore, display quality of the display apparatus is enhanced.