PURPOSE: To preveng the driving performances and exhaust characteristics from worsening even at the time when an engine driving area is selected, in an internal combustion engine belonging to what is known as a fuel leading type.

CONSTITUTION: A basic ignition timing control value θ IGRIC before selecting a driving area is calculated and stored in (S13), and when the driving area is selected, transfer required time TCHANG is calculated (S14), then an air-fuel ratio AFC in the midway of transfer is predicted and estimated according to this transfer required time TCHANG (S15), and further a basic ignition timing control value θIGCB in the midway of the transfer is calculated on the basis of two basic ignition timing control values θIGRIC and IGLEA after the transfer and the air-fuel ratio AFC in the midway of the transfer (S17), and in consideration of a ignition timing delay control compensation value θIGR calculated by a step S18, a final ignition timing θIG is calculated (S19).