To prevent the gain of a helical antenna part from being lowered even when a bar-shaped antenna part is housed.

In a state that a bar-shaped antenna part 410 is housed in a body 300 and only a helical antenna part 420 is arranged on the external side of the body 300, the side of the bar-shaped antenna part 410 viewed from a contact spring 323 for power feeding becomes high impedance because the contact spring 323 for power feeding is connected to the tip side of the antenna part 410, the base end side of the bar-shaped antenna part 410 is connected to a spring 324 for ground and this contact spring 324 is grounded via a reactance element 330.