Abstract: An antenna device used in mobile communication apparatus such as cellular phones, and which achieves good transmission and reception of information in more than one frequency band. Easy and wide ranging adjustment of the impedance properties of the antenna as well as their productive mass production is allowed. The antenna device includes a) a spiral-shaped first antenna element (1) of which one end is open and the other end is electrically connected to a high frequency circuit inside a communication terminal; and b) a second antenna element (2) having both ends being open, and which is insulated from and disposed on either outer or inner surface of the first antenna element (1). The impedance properties of an antenna can be adjusted by changing the disposing position of the second antenna element (2).