There is provided with an antenna device includes a conductive ground plane; an antenna including a radiating element; at least one variable capacitor having one end connected to the conductive ground plane; a plurality of switch elements having one ends connected to the other end of said at least one variable capacitor and other ends connected to the antenna at different locations; a switch controlling unit configured to control an ON/OFF state of each of the switch elements; and a capacitor controlling unit configured to control a capacitance of said at least one variable capacitor.