TWI554003B

Provided are a power supply device, a power supply device control method, and a program, with which the amount of power consumed by a power supply device is reduced effectively and with which the ease of use is improved for the user. A setting is made regarding whether to use an automatic mode, wherein the supply of power to the load is switched automatically from externally input power to the output from an inverter, or to use a standby mode, wherein the switch to inverter output is not executed, when there is a fault with the externally input power. When a fault with the externally input power is detected and the automatic mode has been set, the supply of power to the load is switched to the inverter output. When a fault with the externally input power is detected and the standby mode has been set, a state ensues wherein a selection can be made regarding whether to switch the supply of power to the load from the externally input power to the inverter output. Then, when switching to the inverter output is se