In the PWM circuit of the present invention, a PWM counter counts clock signals. A reference value setting register sets a comparative reference value for determining a duty ratio of a PWM signal. A comparator generates the PWM signals based on a comparative result of the comparative reference value and a count value of the PWM counter. A delay device delays the PWM signal. A switching device switchably outputs the output of the comparator and the output of the delay device in order of time sequence. Thereby, the pulse phase of the PWM signal can be adjusted.