The present invention is directed to a switching power supply apparatus (100) adapted for controlling switching operation of a switching FET (125) which carries out switching of rectified and smoothed output of a primary side rectifying/smoothing circuit (115) by a switching control circuit (130) including a hysteresis low voltage malfunction preventing circuit, wherein lowering time until rated voltage at which constant voltage by self-discharge can be maintained is caused to be longer than time until operating voltage of the low voltage malfunction preventing circuit of the switching control circuit of the primary side at the time of no load, and lowering time until rated voltage at which constant voltage by self-discharge can be maintained is caused to be shorter than time until operating voltage of the voltage malfunction preventing circuit at the time of ordinary load to thereby suppress power consumption as minimum as possible to realize energy-saving at the time of standby.