A planar light source device includes a light source body having at least one partition member in a space formed by first and second substrates, and at least one plasma container. Plasma is generated in a plurality of discharge regions that are connected to one another through the plasma container. The plasma container is disposed at a position adjacent to the partition member to receive a portion of the plasma. According to this configuration, distribution of the plasma in the discharge regions is uniform and luminance of the light generated from the planar light source device is uniform. As a result, the planar light source device implements a good display quality of the LCD apparatus.