A control device employing a computer readable program code, for an engine is provided with an electromagnetic actuator controlling opening and closing operation of an intake valve in response to an electric driving signal. The device determines a target A/F based on a signal corresponding to a requested engine output value and a signal representing a driving condition of the engine, determines a requested intake air flow of a cylinder of the engine based on the signal representing a driving condition of the engine and the target A/F, and determines control values for opening and closing operation of an intake valve based on the requested intake air flow and the target A/F. The control values include at least one of a valve opening timing, a valve opening time and a maximum valve lifting amount of the intake valve. Electric driving signals are generated according to the control values.