To realize a composite antenna whose gain deteriorates little regardless of coming close to or leaving away from the antenna of a large conductor such as a human body.

A plurality of antennas (helical 12 and loop 13) are fed from a common single feed point 14, each antenna, e.g. the loop antenna 13 takes a target value f (e.g. 323 MHz) of resonance frequencywhen a conductor 23 such as human body approaches, while e.g. the helical antenna 12 takes the target value f (e.g. 323 MHz) of resonance frequencywhen the conductor 23 goes away.