PURPOSE: To facilitate garaging of a car in a way that running performance at a reverse step is slowly effected by a method wherein a means to detect pedaling of an accel at a reverse step is mounted to an ignition timing control system, and when the accel at the reverse step is pedaled, an ignition timing is delayed for correction.

CONSTITUTION: At a forward step when an engine is run for running, signals from a crank angle sensor 14 and an airflow meter 15 are inputted to an ignition timing set part 21 to output an ignition signal from a drive part 23. Meanwhile, during pedaling of an accel at a reverse stage, a delay angle amount θL is set to a given amount by means of a retard control part 24. In which case, an ignition timing θIG is corrected by the given amount θL by means of a correction part 22, and an ignition signal is outputted. This constitution enables facilitation of garaging of a car through slow reverse running.