The present invention provides a voltage controlled oscillator having a wide frequency variation range and an oscillation frequency that shows favorable linearity with respect to control voltage. The present invention includes an amplifier circuit 21, a piezoelectric element 22 connected in parallel to the amplifier circuit 21 and forming a feedback loop, variable capacitive elements 24 and 25 respectively connected to an input terminal and an output terminal of the amplifier circuit 21 and having a capacitance value that is dependent on control voltage, and an analog operation circuit 26 that generates a control voltage Vcs based on an inputted control voltage Vc. In this arrangement, the control voltage Vc is applied to the variable capacitive element 24 and the control voltage Vcs generated by the analog operation circuit 26 is applied to the variable capacitive element 25.