<p>A coil (11) is provided with a laminated ceramic capacitor (12) on the inside of the coil. A direct current voltage (DC bias) is applied to an electrode (13) of the laminated ceramic capacitor (12). When the direct current voltage (DC bias) is applied to the laminated ceramic capacitor (12), permittivity e and magnetic permeability µ change, and the electrostatic capacity changes. The inductance value of the coil (11) is changed by changing the magnetic permeability µ.</p>
