1. A plant control system for controlling a plant including an operation signal generation part which calculates an control instruction operation signal for a plant to be controlled by using a measurement signal which has measured an operation state of the plant, the apparatus comprising: an operation signal database which stores the measurement signal of the measured plant; an operation signal database which stores an operation signal for the plant; a numerical calculation execution part which calculates the operation characteristic of the plant; a numerical calculation database which stores the numerical calculation result from the numerical calculation execution part; a simulation model which simulates control characteristic of a plant when the operation signal is supplied to the plant according to information on the numerical calculation result from the numerical calculation database; a learning part which learns the plant operation method by using the model; a learning information database which stores learning information data on the learning part; a control logic database which contains information used for the operation signal outputted from the operation signal generation part; a pattern generation part which generates pattern data expressing a state input based on the learning information data in the learning part with a smaller input number than the model input dimension; a pattern database which stores the pattern data generated in the pattern generation part; and a learning result determination part which selects a learning result having a preferable control effect from the learning result obtained by using a plurality of patterns; wherein the operation signal is calculated from the operation signal generation part according to the learning result selected by the learning result determination part.