A transmitter includes a first PCB having a first surface on which first ground wires and anode wires connecting a light-emitting element and a driver are formed, the anode wires being covered with an insulating section, and a second surface on which a second ground wire coupled to the first ground wires is formed, the second surface being opposite the first surface, a connector that supports the first PCB and is coupled to the second ground wire, a conductive housing that covers the first PCB and the connector, a coupling member in contact with the housing and the first ground wires, the coupling member coupling the housing and the first ground wires, and a second PCB on which the connector and the housing are mounted, the second PCB including a third ground wire that is coupled via the connector to the second ground wire and is coupled to the housing.