@ An oscillating circuit using a phase locked loop which includes a voltage controlled oscillator (6), a phase comparator (3), a low pass filter (4) and a phase extractor (8) has a small circuit scale. Every repeat period of a reference pulse signal being provided to one input terminal of the phase comparator (3) and having a frequency of I/N times of an oscillating frequency of the voltage controlled oscillator, one of leading edges of the output pulses of the voltage controlled oscillator (6) near a leading edge of the reference pulse signal is selectively extracting by the phase extractor (8). The extracted leading edge of the output pulse of the voltage controlled oscillator (6) is provided to another input terminal of the phase comparator (3) and phase-compared with the leading edge of the reference pulse signal by the phase comparator (3). A phase error signal generated from the phase comparator (3) is supplied through the low pass filter (4) to the voltage controlled oscillator (6) as a control voltage thereof in order to stable the oscillating frequency.