A control parameter optimizing system and an operation optimizing apparatus equipped therewith are provided, the system being applicable to an existing plant without modifying the control panel or equipment of the plant, the system further being capable of optimizing the operation control of the plant in accordance with diverse operational requirements. The system includes an objective function setting section, a plant model, and a control parameter optimizing section. The control parameter optimizing section includes an optimization control parameter selecting section and an optimization control parameter adjusting section. The optimization control parameter selecting section selects as an optimization control parameter the control parameter for optimizing an objective function based on control logic information extracted from a power plant. The optimization control parameter adjusting section adjusts the value of the optimization control parameter using the plant model in such a manner as to optimize the objective function.