An illumination device includes a case, a lens body, an LED substrate, a stopper member, and a lead wire. The lens body is fixed in the case. An illuminating part of the lens body projects outward from the upper face opening of the case. The LED substrate is housed in the substrate housing part of the lens body, and the lower surface of the LED substrate is supported by the stopper member. The two lead wires are connected to the LED, led out of the case through insertion holes in the stopper member, and retained by one of lead wire retainers formed on the two side surfaces of the case.