A digital control oscillator circuit includes: a ring oscillator having delay elements delaying a pulse signal; a counter circuit counting the circulation number of the pulse signal; a rough period generation unit acquiring a period setting value as a magnification ratio for a reference clock, and counting the reference clock using an integer part of the ratio to generate a rough period timing; a fraction conversion unit converting a decimal point part of the ratio into the number of the elements passed by the pulse signal to generate a fraction; and an output processing unit selecting a timing when outputs of the ring oscillator and the counter circuit become values corresponding to the fraction as an output timing when a time corresponding to the fraction has passed after the rough period timing, and generating an output signal oscillating at a period represented by the period setting value according to the output timing.