A surface light source device which illuminates a transmission-type liquid crystal display unit from the back surface includes P.times.Q surface light source units with individually controlled light sources. Each of the light sources includes a plurality of light-emitting element units. Each of the light-emitting element units includes at least one red light-emitting element that emits red light, at least one green light-emitting element that emits green light, and at least one blue light-emitting element that emits blue light. The center of mass of a luminance profile based on each of a plurality of red light-emitting elements, a plurality of green light-emitting elements, and a plurality of blue light-emitting elements in each surface light source unit substantially coincides with the center of mass of the surface light source unit.