To provide a variable capacitance capacitor in which the change of a capacity by an applied voltage is large, a Q value is high and temperature characteristics are good.

In the variable capacitance capacitor, a first capacitor C1 and a variable impedance element Z are connected in series, and a second capacitor C2 is connected in parallel with the first capacitor C1 and the variable impedance element Z. The first capacitor C1 and the second capacitor C2 are connected electrostatically. A dielectric material of a high Q value can be used for dielectrics which constitute the first capacitor C1 and the second capacitor C2. Moreover, since the whole change of the capacity can be regulated by the change of the capacity of the variable impedance element Z and can also be regulated according to the degree of coupling and the capacity ratio of the first capacitor C1 and the second capacitor C2 which are coupled electrostatically, it becomes the variable capacitance capacitor in which the change of the capacity by the applied voltage is large, the Q value is high, and the temperature characteristics are good.