The present invention provides a differential voltage control oscillator including: a parallel resonance circuit in which an inductor circuit, a variable capacitance circuit, and a radio-frequency switching circuit are connected in parallel together; and a negative resistance circuit connected in parallel with the parallel resonance circuit. The radio-frequency switching circuit includes: a first switching element; a first capacitive element; a second switching element; a second capacitive element; a control voltage terminal for supplying a common control voltage to the first and second switching control terminals, the control voltage terminal being connected to a virtual ground point for a differential signal generated in the parallel resonance circuit; a first radio-frequency signal reduction section connected between the control voltage terminal and the first switching element; and a second radio-frequency signal reduction section connected between the control voltage terminal and the second switching element.