Abstract: An optimizing device is provided with a target value calculating portion 105 that includes a variable constraint setting portion, a slope constraint setting portion, and a solution calculating portion. The variable constraint setting portion sets constraints for the manipulated variables and control variables. The slope constraint setting portion sets constraints for the slopes for the control variables that include integrating systems. The constraint settings are changed in accordance with the possibility of control variables that include integrating systems going outside of upper and lower limits. The various types of constraints, models for control, and applied optimization evaluating functions that are set/calculated are passed to the solution calculating portion, and optimal target values for minimizing the evaluating function wherein all of the variables are within the constraints are calculated.