A variable capacitor includes a supporting substrate and a plurality of variable capacitance elements, and bias lines. The plurality of variable capacitance elements is formed on the supporting substrate, each of which is composed of a lower-laid first electrode layer, an upper-laid second electrode layer, and a dielectric layer sandwiched therebetween whose dielectric constant changes with direct current bias voltage. In the variable capacitance elements which are adjacent to each other, the second electrode layer of a first variable capacitance element and the first electrode layer of a second variable capacitance element are electrically connected in series with each other. The bias lines each include at least one of resistance component and inductance component for applying the direct current bias voltage. The variable capacitance elements are each connected to the bias lines.