provided is a switching regulator capable of performing stable start - up with a soft - start operation without causing excessive extension of a soft - start time period . in a start - up period , a voltage approximating a feedback voltage is provided as an initial value of a soft - start reference voltage . the feedback voltage and the soft - start reference voltage become substantially equal to each other at a moment when the start - up is completed , to thereby realize a smooth transition of an operating state from the start - up to normal control .