In a digital control pulse generator including a ring oscillator composed of multiple inversion circuits connected in a ring for circulating a pulse, a counter and selectors which turn data of a flip-flop to high when a counted value of the pulse from a terminal of the ring oscillator becomes a value corresponding to ten high order bits of control data, a pulse selector for taking out a clock of the flip-flop from the inversion circuit at the position specified by four bit control data and a delay line and logical product circuit which turn an output signal of the system to a high level for a predetermined time when the output of the flip-flop turns high, a register and adder accumulate the four low order bits of the control data every time the output signal turns high to update the data four bit data. As a result, the ring oscillator may be continuously operated and an oscillation cycle proportional to the control data may be set.