The present invention concerns an antenna device for a portable handset, containing: an earth-connection unit pattern which is provided on one surface of a circuit board; a first antenna pattern which resonates in a first frequency range, and which is provided on the other surface of the circuit board; and a second antenna pattern which resonates at a second frequency range differing from the first frequency range and which is laid out along the edge of the earth-connection unit pattern. The second antenna pattern comprises a zero-order mode resonator (zeroth order mode resonator) containing a capacitor and an inductor. The antenna device described hereinabove makes it easy to secure operating characteristics at mutually differing operating frequencies, can contribute to the miniaturisation of handsets, and can ultimately provide the user with greater convenience of portability and use.