A door latch power supply device includes an electricity storage unit, a charger, a discharger, a contactless power receiver, an input port configured to be connected to an external power supply, an output port configured to be connected to an actuator, and an operation signal receiver configured to receive an operation signal sent in response to an operation for opening a door. While an input voltage input to the input port is higher than or equal to a first input threshold, the charger operates using power supplied from the external power supply so as to cause a storage voltage of the electricity storage unit to become a first storage voltage value, and the discharger outputs power in the electricity storage unit to the output port to place the actuator in the unlatched state in response to the operation signal received by the operation signal receiver. While the input voltage is lower than the first input threshold, the charger operates using power supplied from the contactless power receiver so as to cause the storage voltage to become a second storage voltage value, and then the discharger outputs power in the electricity storage unit to the output port to place the actuator in the unlatched state in response to the operation signal received.