A control device for an engine includes an angular velocity detecting unit that detects the angular velocity of a rotating shaft which is driven according to an output of an engine, an angular acceleration calculating unit that calculates angular acceleration based on the angular velocity detected by the angular velocity detecting unit, a heat generation timing calculating unit that calculates a certain timing when the ratio of an amount of heat generation in a cylinder to the total amount of heat generation of one cycle falls in a predetermined range, based on a change of the angular acceleration calculated by the angular acceleration calculating unit, and a combustion control unit that controls combustion in the cylinder by comparison between the certain timing calculated by the heat generation timing calculating unit and a predetermined heat generation timing reference value.