A control device for a plant includes a manipulation signal generation section for generating the manipulation signal to the plant, a model adapted to simulate a characteristic of the plant, a learning section for generating an input signal of the model so that an output signal obtained by the model simulating the characteristic of the plant satisfies a predetermined target, a learning signal generation section for calculating a learning signal in accordance with a learning result in the learning section, a manipulation result evaluation section for calculating a first deviation as a deviation between a first measurement signal of the plant obtained as a result of application of a certain manipulation signal to the plant and a target value of the measurement signal, and a second deviation as a deviation between a second measurement signal of the plant obtained as a result of application of an updated manipulation signal to the plant and the target value, and a correction signal generation section for generating, when the second deviation calculated by the manipulation result evaluation section is greater than the first deviation, a correction signal of the manipulation signal to be generated by the manipulation signal generation section.