A planar light-emitting device enabling more precise local dimming has a plurality of light-emitting units each including a lightguide plate and a plurality of light sources disposed successively in the lateral width direction of the light-entrance surface and adjacently facing a light-entrance surface of the lightguide plate to emit light into the lightguide plate through the light-entrance surface. The light sources are divided into a plurality of groups successively arranged in the width direction, each group including at least one light source. The lightguide plates of the light-emitting units are mutually adjacently disposed with their light-exiting surfaces being flush with each other. The planar light-emitting device has a light source output control unit that controls the outputs of the light sources for each group.