To provide a variable capacitor, small in a capacity changing rate by high-frequency signal while enlarging the capacity changing rate by a DC bias.

The variable capacitor is provided with a plurality of variable capacity elements C1-C5 connected in series and whose capacities are changed by a DC bias voltage, and bias lines B11-B15, B21-B25 connected to respective variable capacity elements C1-C5 to impress the DC bias voltage. In such a variable capacitor, the bias lines B11-B15, B21-B25 are provided with at least one of a resistance component or an inductance component having a capacity enough to intercept a high-frequency signal, and the partial pressure of the DC bias voltage applied on each bias lines B11-B15, B21-B25 is smaller than that of the DC bias voltage applied on each variable capacity elements C1-C5 while values of resistances of the bias lines B11-B15, B21-B25 are reduced as temperatures of the lines are raised.