A combustion condition for each of plural cylinders included in an
internal combustion engine is set by the following control that is
performed according to an intake air amount in each of the plural
cylinders. A reference cylinder is set to a cylinder in which the intake
air amount is smallest, and a fuel injection amount for the reference
cylinder is set to a fuel injection amount for realizing a stoichiometric
air-fuel ratio. The air-fuel ratio in each of the cylinders other than
the reference cylinder is set according to the intake air amount in each
of the cylinders such that the torque equal to reference torque generated
in the reference cylinder is generated. When this setting is performed,
air-fuel ratios that are out of a predetermined region in the vicinity of
the stoichiometric air-fuel ratio (i.e., air-fuel ratios that are in an
avoidance region) are excluded. With respect to a cylinder in which the
torque equal to the reference torque cannot be generated only by setting
the air-fuel ratio, correction of the ignition timing is further
performed so as to suppress a difference between the torque generated in
the cylinder and the reference torque.