An oscillator includes: a piezoelectric material to vibrate; a first inverting amplifier; a second inverting amplifier; a first output electrode to apply an output signal of the first inverting amplifier to the piezoelectric material; a second output electrode to apply an output signal of the second inverting amplifier to the piezoelectric material; a first input electrode to receive a voltage signal generated by the piezoelectric material and output the voltage signal to the first inverting amplifier; and a second input electrode to receive the voltage signal and output the voltage signal to the second inverting amplifier, wherein the first and second output electrodes are coupled to the piezoelectric material so that faces of the piezoelectric material move in opposite directions, and the first and second input electrodes are coupled to the piezoelectric material so that the voltage signals are input to the first and second input electrodes.