The present invention achieves, using simple circuits, timing synchronization among ECUs of an electronic control device which is configured from a driver ECU, a sensor ECU, and an integrated ECU which are connected over a network. This electronic control device is provided with a driver ECU for driving various loads for vehicular control, a sensor ECU for sampling various sensor signals, and an integrated ECU which is connected to the driver ECU and sensor ECU over a network and calculates command values to the various loads in accordance with various sensor data, the electronic control device being characterized in that the driver ECU has timer D for generating internal timing, the sensor ECU has timer S for generating internal timing, and the integrated ECU has timer M serving as a reference for timer D and timer S.