An Al0.95Ga0.05N:Mg (25 nm) single electron barrier can stop electrons having energy levels lower than the barrier height. Meanwhile, a 5-layer Al0.95Ga0.05N (4 nm)/Al0.77Ga0.23N (2 nm) MQB has quantum-mechanical effects so as to stop electrons having energy levels higher than the barrier height. Thus, electrons having energy levels higher than the barrier height can be blocked by making use of multiquantum MQB effects upon electrons. The present inventors found that the use of an MQB allows blocking of electrons having higher energy levels than those blocked using an SQB. In particular, for InAlGaN-based ultraviolet elements, AlGaN having the composition similar to that of AlN is used; however, it is difficult to realize a barrier having the barrier height exceeding that of AlN. Therefore, MQB effects are very important. Accordingly, it becomes possible to provide element technology for further improving deep UV light emission intensity using, as a light-emitting layer material, an AlGaInN-based material and, in particular, an AlGaN-based material.