Internal combustion engine controller

A torque correspondence value (e.g., estimated indicated torque) is determined. The degree of torque correspondence value variation in a plurality of previous cycles is digitized as a variation index value (e.g., locus length). If the variation index value is smaller than a predetermined first judgment value, the intake air amount of an internal combustion engine is corrected. If the variation index value is not smaller than the first judgment value, the ignition timing of the internal combustion engine is corrected. If the variation index value is not smaller than a second judgment value, which is greater than the first judgment value, the ignition timing and fuel injection amount of the internal combustion engine are both corrected.