Abstract: The present invention relates to an automatic starting and stopping apparatus for an engine, which prolongs the lives of mechanical components such as a starter motor and which is applicable also to automatic vehicles. The automatic starting and stopping apparatus for an engine comprises a vehicle-to-vehicle distance sensor 29, which detects whether the distance from the preceding vehicle is less than a preset value, a signal color identifying and detecting device 30, which identifies whether the lit color of the signal is yellow or red, a car speed sensor 15, and a control circuit 31, which performs automatic start and stop of the engine in accordance with the detection results of the vehicle-to-vehicle distance sensor 29 and the signal color identifying and detecting apparatus 30.