Electronic Control Device

To obtain a highly reliable electronic control device capable of reliably causing a microcomputer to perform normal termination and normal re-activation by controlling a power supply voltage. According to the present invention, an electronic control device includes a microcomputer , a power supply control unit that controls a power supply voltage of the microcomputer, and a capacitor provided between the power supply control unit and the microcomputer. The power supply control unit includes a power supply unit that supplies a first power supply voltage V to the microcomputer by turning ON an activation signal for activating the microcomputer, and stops the supply of the power supply voltage by turning the activation signal OFF, a reset control unit that generates a Low reset signal by turning the activation signal OFF, and a discharge control unit that discharges electric charges of the capacitor when acquiring the Low reset signal.