ENGINE CONTROL DEVICE

An engine control device includes that controls an air excess rate of each of N (an integer of 2 or more) cylinders by controlling an intake air amount and a fuel injection amount of each of the N cylinders; and a determination unit for determining whether or not there is a request to switch the air excess rate controlled by λ to λ different from λ. When an affirmative determination is made by the determination unit, the control unit controls the air excess rate such that a proportion of L combustion strokes at λ to consecutive K (an integer greater than N) combustion strokes increases from 0% to 100% in M (an integer greater than N) steps.