In a portable wireless device (100), a thin coaxial cable (121) connects electrical signals, which are transmitted from first and second circuit members (111, 112) stored in first and second casings (101, 102). The casings are connected to be opened and closed by a third casing (103) which has a hinge section (104). The first and second circuit members (111, 112) are connected to each other by a connecting element (122) with a reactance element (123) arranged in between for switching reactance. The device is provided with first, second and third antennas (131, 132, 133) in the vicinity of the hinge section (104) of the second housing (102). Even if the first casing (101) rotates substantially 90 degrees within the same flat surface, excellent antenna characteristics can be obtained with a discretionary frequency by switching connection impedance of the first and second casings (101, 102), corresponding to frequencies used in terminal states, respectively.Thus, the casings are connected in the ideal manner by switching the connection impedance with a discretionary frequency between the casings, and excellent antenna characteristics are obtained with a discretionary frequency for each discretionary state.