PURPOSE: To prevent the invalid length part of a whip antenna from being generated without losing the merit of separately using a part for standby and a main body part even when the antenna is extended.

CONSTITUTION: This whip antenna is composed of a main body part 5 which can enter/leave from casing and the part for standby provided on the free end part of the main body part 5 and composed of a loading coil 8 and a cap 7 or the like at positions adjacent to the outer face of the casing when the main body part 5 is housed in the casing and provided with a connecting means composed of a bushing 2 for connecting a circuit in the casing respectively to the part for standby at the time of housing the main body part 5 in the casing and to the main body part 5 at the time of extending the main body part 5 out of the casing and means for disconnecting the part for standby from the main body part 5 when the main body part 5 is housed in the casing. Thus, even at the time of speaking, the part for standby can be effectively used as a part of the main body part 5, the invalid length of the antenna can be canceled, and the regulated valid length can be fully used.