An electrical signal is fed from one terminal of an antenna element, and the other terminal thereof is terminated by a variable reactance circuit. A reactance value of the variable reactance circuit is changed according to use state of a device to optimally set its directivity. Matching conditions at an electricity feeding point are controlled to match an impedance of the electricity feeding point which fluctuates according to the value of the variable reactance circuit. With the above construction, there are provided an antenna device that is downsized, can control its directivity, and does not deteriorate a communication quality depending on a use state, and a radio communication apparatus provided with the antenna device.