PURPOSE: To prevent the influence given to the radiation characteristic of an antenna when a human body approaches to or touches a portable radio equipment.

CONSTITUTION: An antenna element 1 is attached to a casing 4 containing an electronic circuit by means of a slender metallic bar 9 which can effectively function as a stub. That is, a conductor surface is formed at least at a part of the casing 4 so that the parallel lines are formed by the conductor surface and the bar 9. Then one of both ends of the bar 9 is short-circuited on the conductor surface as a short circuit terminal with the other end of the bar 9 used as an open terminal respectively. The element 1 is attached to the open terminal, and the distance L is effectively set at 1/4 working wavelength between open and short circuit terminals of the bar 9. Meanwhile the hot side of a feeding line 3 is connected to the element 1 with the cold side connected to the bar 9 respectively. In such a constitution, a complicated antenna current is never caused on the surface of the casing 4 and the influence can be reduced to the body of a person who is holding a portable radio equipment.