FIG. 4 is an example of such step-up type switching regulator 11a.In FIG. 4, the step-up circuit 1e and the diode D in FIG. 1 are eliminated and a diode Da is inserted between the coil L and the capacitor C. The P channel switching MOS transistor 1c in FIG. 1 is replaced by an N channel MOS transistor 1f, andthe N channel switching MOS transistor if is provided between a connection point Na of the