A process control system includes a client computer which prepares a correlation between a reference monitored value of apparatus information and a feature quantity, a manufacturing execution system which prepares a processing recipe describing, as a first setting value in an actual manufacturing process, a value of the control parameter, an apparatus information collection section which collects an objective monitored value of the apparatus information in operation of the actual manufacturing process with the first setting value, a feature quantity calculation section which calculates a value of a feature quantity corresponding to the objective monitored value based on the correlation, a parameter calculation section which calculates a second setting value in the actual manufacturing process on the basis of the value of the feature quantity, and an apparatus control unit which changes the processing recipe with the second setting value being as a setting value of the second step.