A power supply controller can include a switching element electrically connected between a power source and a load, an anomaly detecting circuit capable of outputting an abnormal signal, a power supply circuit which generates a constant voltage, a holding circuit which is activated by being supplied with the constant voltage generated by the power supply circuit, continuously outputs a shutoff signal to cause the switching element to perform a shutoff operation on the basis of the abnormal signal, an output circuit, such that if a first off signal is being inputted from an external source, the first off signal continues for a predetermined period of time after the start of the continuous output of the shutoff signal, outputs a second off signal, and an electrical conduction circuit structured to enable the power supply circuit into conduction in response to an on signal from an external source and enable the power supply circuit out of conduction if the second off signal is outputted.