PURPOSE: To prevent an increase in brokes by changing over operation to a manual intervening arithmetic part when manual intervention occurs in changing the papermakihg speed and exchanging the brand in papermaking and applying an operation pattern to a paper quality control part.

CONSTITUTION: An operation terminal is operated with a paper quality control part 80 according to an operation pattern fed from a changeover part 75 to carry out control so as to make measured values of a sensor (BM) coincide with target value. A predictive arithmetic part 60 is normally adopted by the changeover part 75 and a manual intervention arithmetic part 70 is adopted in manual intervention. An operation pattern in changing the papermaking speed and exchanging brand in the papermaking in the case of no change in process conditions of the paper machine is computed and outputted with the predictive arithmetic part 60. An operation pattern in changing the papermaking speed and exchanging the brand in the papermaking in the case of a change in the process conditions of the paper machine is computed and outputted with the manual intervention arithmetic part 70. The computation in the arithmetic part 70 is performed by application of parameters according to the process conditions.