There is provided an electronic device that can heat an auxiliary battery as a standby power supply and check a function of the auxiliary battery with a simpler configuration. The device is provided with a heater resistor for heating an auxiliary battery incorporated in an in-vehicle emergency notification device as a standby power supply for a main battery, and is also provided with first and second power supply switches for forming first and second power supply paths for supplying power from the main battery and the auxiliary battery to the heater resistor, respectively. A control circuit controls the first and second power supply switches to form the power supply paths so as to conduct a current to the heater resistor.