A control device for internal combustion engine, the control device being applied to an internal combustion engine having: at least one supercharger containing a turbine provided on an exhaust gas passage of the engine and driven by an exhaust gas being entered into the turbine through an approach zone, a compressor provided on an intake air passage of the engine and compressing air flowing through the intake air passage by being driven upon the turbine being driven, an opening-area control member changing an amount of energy of the exhaust gas entered into the turbine by controlling an opening-area of the approach zone depending on a first instruction; and at least one control valve changing an amount of energy of the exhaust gas entered into the turbine by controlling a valve-opening degree of the control valve depending on a second instruction, the control device comprising a control means for determining a control rule of the opening-area of the approach zone based on a target difference in the valve-opening degree and a parameter relating to a response-time length upon the second instruction being given to the control valve at an instruction time point so as to change the valve-opening degree by the target difference, and giving the first instruction to the opening-area control member so as to start controlling the opening-area of the approach zone in accordance with the control rule at the instruction time point as starting time point, the control rule of the opening-area being a relationship of the opening-area of the approach zone with respect to time, the target difference being an absolute value of a difference between the valve-opening degree of the control valve at the present moment and the target valve-opening degree at the present moment, and the response-time length being a required length of time between a first time point where an instruction is given to the control valve so as to change the valve-opening degree from a first valve-opening degree to a second valve-opening degree and a second time point where the valve-opening degree of the control valve matches to the second valve-opening degree. the control device being applied to an internal combustion engine having: at least one supercharger containing a turbine provided on an exhaust gas passage of the engine and driven by an exhaust gas being entered into the turbine through an approach zone, a compressor provided on an intake air passage of the engine and compressing air flowing through the intake air passage by being driven upon the turbine being driven, an opening-area control member changing an amount of energy of the exhaust gas entered into the turbine by controlling an opening-area of the approach zone depending on a first instruction; and at least one control valve changing an amount of energy of the exhaust gas entered into the turbine by controlling a valve-opening degree of the control valve depending on a second instruction, the control device comprising a control means for determining a control rule of the opening-area of the approach zone based on a target difference in the valve-opening degree and a parameter relating to a response-time length upon the second instruction being given to the control valve at an instruction time point so as to change the valve-opening degree by the target difference, and giving the first instruction to the opening-area control member so as to start controlling the opening-area of the approach zone in accordance with the control rule at the instruction time point as starting time point, the control rule of the opening-area being a relationship of the opening-area of the approach zone with respect to time, the target difference being an absolute value of a difference between the valve-opening degree of the control valve at the present moment and the target valve-opening degree at the present moment, and the response-time length being a required length of time between a first time point where an instruction is given to the control valve so as to change the valve-opening degree from a first valve-opening degree to a second valve-opening degree and a second time point where the valve-opening degree of the control valve matches to the second valve-opening degree.