A directivity controllable array antenna with a variable phase shifter is provided which is stable and has a small waveform and intermodulation distortion, excellent high power handling capability and low-loss. In an array antenna with a variable phase shifter, the variable phase shifter has a transmission line, and a variable capacitance capacitor is connected to a terminal of a ground side of the transmission line. In the variable capacitance capacitor, a plurality of variable capacitance elements each using a thin film dielectric layer whose dielectric constant changes in accordance with an applied voltage are connected between an input terminal and an output terminal, in parallel to each other with respect to direct current component and in series with each other with respect to high frequency component.