According to one embodiment, a light-emitting element comprises: a first electrically-conductive semiconductor layer, a second electrically-conductive semiconductor layer; and an active layer which is disposed between the first electrically-conductive layer and the second electrically-conductive layer, and in which a well layer and a barrier layer are alternately laminated at least once. The active layer comprises: a first region which is disposed between a neighboring barrier layer and well layer, and linearly reduces the energy band gap; and a second region which is disposed between a neighboring well layer and barrier layer, and linearly increases the energy band gap. In the well layer, at least one first region and second region neighboring the same well layer have mutually different thicknesses.