A gyro sensor includes a vibrator and a drive circuit. A PWM drive signal is applied to a pair of electrodes of the vibrator. The drive circuit outputs a high level signal and a low level signal to the electrodes as the PWM drive signal. The high level signal and the low level signal have potentials higher and lower than that of the reference signal, respectively. The drive circuit outputs the high level signal to one of the pair of electrodes and the low level signal to the other of the pair of electrodes.