There is provided a voltage controlled oscillator using a Colpitts circuit capable of suppressing deterioration (decrease) in variable range (adjustable range) of an output frequency due to the influence of an inductance component on a conductive line, which connects a connection point between two capacitors of a feedback part and an emitter of a transistor. In a VCO using a Colpitts circuit, with respect to capacitors 22, 23 of a feedback part 2, a first feedback capacitance element (capacitor) 22 is disposed so as to directly couple a terminal for base (connection part 7) and a terminal for emitter on a base substrate 5, to which a terminal part 8 (T1) extending from a base of a transistor 21 and a terminal part 8 (T2) extending from an emitter of the transistor 21 are fitted, respectively, and a second feedback capacitance element (capacitor) 23 is disposed so as to directly couple the terminal for emitter and the terminal for grounding (ground electrode 51).