A power supply device includes a first rectifying unit that converts the AC power passed through an input unit into DC power, a power-factor improving unit that improves a power factor of the DC power output from the first rectifying unit, a first power storage unit that stores the DC power passed through the power-factor improving unit and supplies the stored DC power to a load side, a second rectifying unit connected to a portion where the input unit is connected to the AC power supply, the second rectifying unit converting the AC power into the DC power, a second power storage unit that stores the DC power passed through the second rectifying unit, and a control unit that operates using the electric power stored in the second power storage unit and, when a short-circuit failure occurs in the power-factor improving unit, performs control for interrupting the input unit.