In a first series circuit of a power supply control device, a first switch and a first resistor are connected in series. In a second series circuit, a second switch and a second resistor are connected in series. The second series circuit is connected in parallel to the first series circuit. An electric current detection circuit detects an electric current value of an electric current flowing through the first resistor. In a case where specific data is stored in a storage unit, a control unit (open failure detection unit) detects an open failure of the first switch or the second switch on the basis of the electric current value detected by the electric current detection circuit. In a case where the storage unit does not store the specific data, the control unit does not detect the open failure.