In a switching power supply apparatus, the change in the voltage VOUT at the OUT terminal is transmitted to a V-I conversion circuit via an error amplification circuit and to an I-V conversion circuit, whereby the output voltage signal VL of the I-V conversion circuit is changed. The peak value of the drain current of a switching device changes since VL is used as the reference voltage of an overcurrent detection circuit. VL is transmitted to an intermittent oscillation control circuit having a hysteresis characteristic, and the switching device is subjected to intermittent oscillation. In the switching power supply apparatus, further reduction in power consumption can be attained during standby, particularly in a no-load condition.