A full-wave rectifier-circuit (110) supplies a pulsating-DC-voltage (Vdc) obtained by rectifying an AC voltage (Vac). A switching element (T131) consisting of a power supply apparatus (130) is turned on during a fixed on-period Mon and turned off during a fixed off-period Moff (=M-Mon) in each fixed control period M. When the switching element (T131) is turned on, a current (I2) caused by electric charge accumulated in a capacitor (C132) flows through a path formed by an inductor (L131) and the switching element (T131). When the switching element (T131) is turned off, a flywheel current (I3) caused by electromagnetic energy accumulated in the inductor (L131) flows through a path formed by a diode (D131) and a parallel circuit consisting of a capacitor (C131) and a load (120), and a current (I1) is supplied from the full-wave rectifier circuit (110) to the capacitor (C132) via an inductor (L132). A power supply apparatus (100) is configured such that the current (I1) continues to flow through the capacitor (C132) while the switching element (T131) is off.