A mobile wireless device enables effective use of space in a case while reducing degradation of antenna gain and maintaining communication quality even if a plurality of antennas having different frequency bands are arranged close to one another. A magnetic antenna has a first switch unit, a second switch unit, and a concentrated constant circuit which are added to a wiring pattern at the side near to a main antenna, so that a first path and a second path can be selected. Under a predetermined condition, a CPU controls the first switch and the second switch to electrically connect terminal (A1) to terminal (B1) and electrically connect terminal (A2) to terminal (B2), thereby forming the first path; and electrically connect terminal (A1) to terminal (C1) and electrically connect terminal (A2) to terminal (C2), thereby forming the second path connected via the concentrated constant circuit.