PURPOSE: To surely detect abnormal resetting of a computer in controlling, by providing a detecting means for detecting the state just before a computer is made into the reset state, and determining a processing content of the computer on the basis of the detected state of the detecting means just after the computer is started.

CONSTITUTION: Electric power is supplied to a 5V power circuit through a transistor 18, and a 5V power source Vcc is formed on the basis of this electric power. The 5V power source Vcc formed by the 5V power circuit 19 is supplied to a microcomputer 11 and a reset circuit 20. The reset circuit 20 resets the microcomputer 11 when power-on is reset in starting of a controller, when the 5V power source Vcc is lowered, or when abnormalities are generated on a watch dog signal to be supplied from a port P6 of the microcomputer 11.