A light-emitting device includes an insulating base member having thermal conductivity of 10 W/m·K or more; a light-emitting element that has a cathode electrode and an anode electrode and is provided on a front surface side of the base member; a capacitive element that is provided on the base member and supplies an electric current to the light-emitting element; and a reference potential wire that is provided on a rear surface side of the base member and is connected to an external reference potential. The reference potential wire is connected to the capacitive element and is insulated from the cathode electrode and the anode electrode.