A semiconductor light-emitting device can include a submount on which a semiconductor light-emitting element is mounted. The device can have a high light utilization efficiency with high reliability and can achieve a reduction in manufacturing cost as well as a decrease in size. The submount can have a reverse trapezoidal cross section having an upper surface that is larger than a bottom surface of the semiconductor light-emitting element. An adhesive can be used to fix the submount to the base board such that, when the submount is observed from above the semiconductor light-emitting element, the adhesive is not seen from above. In this state, the semiconductor light-emitting element can be connected to the base board via a bonding wire.