In a light-emitting device (10), a control circuit (30) controls the lighting-up of a semiconductor light-emitting element (20). A heat-dissipating substrate unit (13) supports the semiconductor light-emitting element (20) and the control circuit (30) so as to recover the heat produced by each. The heat-dissipating substrate unit (13) supports the semiconductor light-emitting element (20) such that a light-emitting part of said semiconductor light-emitting element (20) protrudes farther, in the direction of the main optical axis of said light-emitting part, than the control circuit (30). The heat-dissipating substrate unit (13) comprises: a heat-dissipating substrate (15) that supports the control circuit (30); and a support member (14) that protrudes from the heat-dissipating substrate (15) and supports the semiconductor light-emitting element (20). Said heat-dissipating substrate (15) and support member (14) are formed separately and affixed to each other by an adhesive that has a thermal conductivity of at least 3 W/m·K.
