ELECTRONIC CONTROL UNIT

Provided is an electronic control unit mounted on an electrically driven vehicle, the electronic control unit being excellent in reliability and convenience in which recovery is easy while reliably shutting off a high-voltage power supply line at the time of collision of the vehicle or failure of a power supply shutoff circuit. The electronic control unit includes: an external load switching element that drives an external load; a controller that drives the external load switching element; a shutoff transistor that shuts off connection between an internal GND and an external GND or connection between an internal power supply system and an external power supply system; a diagnosis circuit that receives, as input, a diagnosis signal of a control circuit that controls the external load by the external load switching element, and a diagnosis signal of the controller, and outputs a diagnosis result; and an output holding circuit that holds an output signal of the diagnosis circuit, wherein the shutoff transistor shuts off the connection between the internal GND and the external GND or the connection between the internal power supply system and the external power supply system on the basis of the signal held by the output holding circuit.