AIR-FUEL RATIO CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

An integral operation in an upstream target-value varying part is stopped in response to transition to a fuel cutoff state to maintain an integral value concerning a downstream side. Thereafter, at a time of removal of the fuel cutoff state, a cumulative-air-intake-amount detecting part detects a cumulative air amount of air taken into an engine. Then, when the cumulative air amount reaches a predetermined air amount, an integral-operation-stop/restart controlling part restarts the integral operation in the upstream target-value varying part to update integral values concerning the downstream side in a time sequence.