PURPOSE: To miniaturize the size of the voltage controlled oscillator ' by adopting plural chip layer capacitors connected in parallel via a connection pattern formed on a board for a resonance capacitor of a resonance circuit so as to adjust the capacitance of the capacitor through the interruption of the pattern.

CONSTITUTION: In order to adjust a variable range of an oscillated frequency from the oscillator, a connection pattern CP 5 is cut by using a laser beam to separate a chip capacitor Ce' from a resonance circuit 1. Since the capacitance of a resonance capacitor C2 is decreased, the resonance frequency of the circuit 1 is shifted higher and the variable range of the oscillating frequency adjusted by a varactor diode VD is shifted to a higher range. Thus, when all of chip lamination capacitors Ca'-Ce' are connected to each other, the resonance frequency of the circuit 1 is set lower than a prescribed frequency so as to shift the frequency variable range adjusted by the diode VD to a lower frequency than the predetermined frequency.