In a semiconductor light-emitting element, a first DBR and a second DBR, with a specified spacing left between them, form a resonator, and a single quantum well active layer is positioned at the loop of a standing wave within this resonator. The single quantum well active layer is composed of a Ga0.5In0.5P well layer and a pair of (Al0.5Ga0.5)0.5In0.5P barrier layers, which sandwiches the Ga0.5In0.5P well layer therebetween. The impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is higher than that of the Ga0.5In0.5P well layer. For example, the impurity concentration of the Ga0.5In0.5P well layer is set to 2×1016 cm−3, while the impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is set to 2×1018 cm−3.