A multiband antenna applied to a portable terminal is provided to reduce degradation of telephone call capacity due to influence of a human body and hand in the call of a portable terminal by being electrically coupled from the multiband antenna with interconnection and resonate about a plurality of frequency bands for using. A multiband antenna is connected to a portable terminal as a mutual subordination in order to be operated according to signals transmitted and received. A resonant cavity(350) resonates about a plurality of frequency bands as the end tip of the multiband antenna is located in fixed interval. The multiband antenna comprise: a basic body of different many sides having dielectric constant; a first feeding unit(330) for delivering suddenly the signal transmitted and received from the portable terminal; and a first antenna.
