An electronic control unit for automotive comprising a series regulator and a microcomputer, wherein the series regulator is to be connected to an in-vehicle power supply for supplying a voltage to the microcomputer, the series regulator comprising: a first capacitor that has one end to be connected to a positive electrode of the in-vehicle power supply and the other end to be connected to a negative electrode of the in-vehicle power supply; a second capacitor that has one end connected to an input terminal of the microcomputer and the other end to be connected to the negative electrode of the in-vehicle power supply; and a transistor that has an input terminal connected to the one end of the first capacitor and an output terminal connected to the input terminal of the microcomputer; wherein the series regulator is characterized in further comprising: an output control circuit that has an output connected to an output control terminal of the transistor and is configured to control driving of the transistor; wherein the microcomputer includes a stop processor that is configured to store information required for a subsequent start when a voltage applied between both ends of the first capacitor falls below a given voltage, characterized in that the series regulator further comprises: a resistive element that has one end connected to the output control terminal of the transistor and the output of the output control circuit; a third capacitor that has one end connected to the other end of the resistive element and the other end to be connected to the negative electrode of the in-vehicle power supply; and a fourth capacitor that is connected in parallel to the resistive element, wherein one end of the fourth capacitor is connected to the one end of the resistive element, and the other end of the fourth capacitor is connected to the other end of the resistive element. an output control circuit that has an output connected to an output control terminal of the transistor and is configured to control driving of the transistor; wherein the microcomputer includes a stop processor that is configured to store information required for a subsequent start when a voltage applied between both ends of the first capacitor falls below a given voltage, characterized in that the series regulator further comprises: a resistive element that has one end connected to the output control terminal of the transistor and the output of the output control circuit; a third capacitor that has one end connected to the other end of the resistive element and the other end to be connected to the negative electrode of the in-vehicle power supply; and a fourth capacitor that is connected in parallel to the resistive element, a resistive element that has one end connected to the output control terminal of the transistor and the output of the output control circuit; a third capacitor that has one end connected to the other end of the resistive element and the other end to be connected to the negative electrode of the in-vehicle power supply; and a fourth capacitor that is connected in parallel to the resistive element, wherein one end of the fourth capacitor is connected to the one end of the resistive element, and the other end of the fourth capacitor is connected to the other end of the resistive element.