An electronic control device, comprising: a first analog-to-digital converter configured for receiving a reference voltage (Vref) for analog-to-digital conversion output from a first voltage source; a voltage (Vcc) for abnormality determination output from a second voltage source independent of the first voltage source, said voltage (Vcc) for abnormality determination having a value lower than the reference voltage (Vref); and a control signal being an analog signal, said first analog-to-digital converter being configured for converting the control signal and the voltage (Vcc) for abnormality determination into digital data by using the reference voltage (Vref); a first abnormality determination means for monitoring the voltage value of the voltage (Vcc) for abnormality determination based on the digital data input from the first analog-to-digital converter to perform abnormality determination for the first analog-to-digital converter and the reference voltage (Vref), and determining that one of the first analog-to-digital converter and the reference voltage (Vref) is abnormal when the voltage value of the voltage (Vcc) for abnormality determination falls outside a predetermined normal range; and a first processor for performing a control operation for a predetermined control subject by using the digital data corresponding to the control signal that is input from the first analog-to-digital converter; characterized by a second analog-to-digital converter configured for receiving the reference voltage for analog-to-digital conversion output from said first voltage source; and the voltage (Vcc) for abnormality determination output from said second voltage source independent of the first voltage source, said second analog-to-digital converter being configured for converting the voltage (Vcc) for abnormality determination into digital data by using the reference voltage (Vref); and a second abnormality determination means for monitoring the voltage value of the voltage (Vcc) for abnormality determination based on the digital data input from the second analog-to-digital converter to perform abnormality determination for the second analog-to-digital converter and the reference voltage (Vref), and determining that one of the second analog-to-digital converter and the reference voltage (Vref) is abnormal when the voltage value of the voltage (Vcc) for abnormality determination falls outside a predetermined normal range. a first analog-to-digital converter configured for receiving a reference voltage (Vref) for analog-to-digital conversion output from a first voltage source; a voltage (Vcc) for abnormality determination output from a second voltage source independent of the first voltage source, said voltage (Vcc) for abnormality determination having a value lower than the reference voltage (Vref); and a control signal being an analog signal, said first analog-to-digital converter being configured for converting the control signal and the voltage (Vcc) for abnormality determination into digital data by using the reference voltage (Vref); a first abnormality determination means for monitoring the voltage value of the voltage (Vcc) for abnormality determination based on the digital data input from the first analog-to-digital converter to perform abnormality determination for the first analog-to-digital converter and the reference voltage (Vref), and determining that one of the first analog-to-digital converter and the reference voltage (Vref) is abnormal when the voltage value of the voltage (Vcc) for abnormality determination falls outside a predetermined normal range; and a first processor for performing a control operation for a predetermined control subject by using the digital data corresponding to the control signal that is input from the first analog-to-digital converter; characterized by a second analog-to-digital converter configured for receiving the reference voltage for analog-to-digital conversion output from said first voltage source; and the voltage (Vcc) for abnormality determination output from said second voltage source independent of the first voltage source, said second analog-to-digital converter being configured for converting the voltage (Vcc) for abnormality determination into digital data by using the reference voltage (Vref); and a second abnormality determination means for monitoring the voltage value of the voltage (Vcc) for abnormality determination based on the digital data input from the second analog-to-digital converter to perform abnormality determination for the second analog-to-digital converter and the reference voltage (Vref), and determining that one of the second analog-to-digital converter and the reference voltage (Vref) is abnormal when the voltage value of the voltage (Vcc) for abnormality determination falls outside a predetermined normal range.