To allow an operator located at a remote place to easily confirm it with a light emission of a very weak power when the operator at the remote place is informed of the reaction of an operation object part of an automobile in response to a radio signal sent from the outside of a cabin through remote control.

The inside of a case-shaped base 20 that supports a base end of an antenna rod 10 extended upward and is mounted on a roof 1 is provided with an LED 25 that is lighted in response to a response signal generated when an operation object part reacts. An optical fiber 11 that leads a light emission of the LED 25 made incident from the base end to the tip of the antenna rod 10 is contained in the antenna rod 10. A light projection section 18 that projects the light emission made incident from the tip to surrounding is provided to the tip of the antenna rod 10.