To provide a technique capable of contributing to reducing the number of components of a voltage-controlled oscillator using a Colpitts oscillator circuit in which a series circuit of a feedback capacitance component C1 and a coupling capacitance component C2 is connected to an amplifying transistor.

A first transmission line 41 is connected to a base of a transistor 21, and a second transmission line 42 is connected between an emitter of the transistor 21 and a ground. The first transmission line 41 and the second transmission line 42 are placed near each other to form an interline capacitance component in between. The interline capacitance component is used as the feedback capacitance component C1, and a parasitic capacitance component formed between the second transmission line 42 and the ground is used as the coupling capacitance component C2.