To secure sufficient braking force during automatic stopping of an engine.

An engine is automatically stopped when a specified automatic condition is effected during actuating the engine which is mounted on a car having a negative pressure boosting brake. When a specified automatic starting condition is effected during automatic stopping of the engine, the engine is automatically started. In such an automatic starting control device, a car speed sensor is arranged for sensing the speed of the running car. A control means is provided for automatically starting the engine when the car speed exceeds zero during automatic stopping of the engine.