A portable radio apparatus, comprising: an antenna for transmitting and receiving a radio signal; and a radio circuit for decoding and encoding radio signals further comprising a matching circuit connected to the antenna, for providing an impedance match between the antenna and the radio circuit; wherein: the antenna is capacitive the matching circuit includes an inductive element connected in parallel to the antenna; and the inductive element has a Q factor more than a predetermined value, the Q factor being expressed as follows: Q = omega L / R wherein R indicates a resistance component, L is an inductance component, and omega designates an angular frequency of the radio signal, the antenna and the inductive element resonate at a frequency different from a resonance frequency f1 of the antenna wherein f1 is a frequency in the vicinity of an upper limit of a desired frequency band, this parallel circuit causing resonance at a frequency f2 in the vicinity of a lower limit of the desired frequency band, such that a two-resonance characteristic is achieved, the Q factor of the inductive element being selected to be 40 or more, thus increasing the radiation efficiency in the free space position. an antenna for transmitting and receiving a radio signal; and a radio circuit for decoding and encoding radio signals further comprising a matching circuit connected to the antenna, for providing an impedance match between the antenna and the radio circuit; wherein: the antenna is capacitive the matching circuit includes an inductive element connected in parallel to the antenna; and the inductive element has a Q factor more than a predetermined value, the Q factor being expressed as follows: Q = omega L / R wherein R indicates a resistance component, L is an inductance component, and omega designates an angular frequency of the radio signal, the antenna and the inductive element resonate at a frequency different from a resonance frequency f1 of the antenna wherein f1 is a frequency in the vicinity of an upper limit of a desired frequency band, this parallel circuit causing resonance at a frequency f2 in the vicinity of a lower limit of the desired frequency band, such that a two-resonance characteristic is achieved, the Q factor of the inductive element being selected to be 40 or more, thus increasing the radiation efficiency in the free space position. the antenna is capacitive the matching circuit includes an inductive element connected in parallel to the antenna; and the inductive element has a Q factor more than a predetermined value, the Q factor being expressed as follows: Q = omega L / R wherein R indicates a resistance component, L is an inductance component, and omega designates an angular frequency of the radio signal, the antenna and the inductive element resonate at a frequency different from a resonance frequency f1 of the antenna wherein f1 is a frequency in the vicinity of an upper limit of a desired frequency band, this parallel circuit causing resonance at a frequency f2 in the vicinity of a lower limit of the desired frequency band, such that a two-resonance characteristic is achieved, the Q factor of the inductive element being selected to be 40 or more, thus increasing the radiation efficiency in the free space position.