PURPOSE: To improve the quick responsiveness of tension control and to improve the accuracy of a product by approximating the maximum error through a suitable frequency weight filter after the basic model formula of a tension generation process is determined, guiding a control rule through the H∞ control theory and performing a stable tension control.

CONSTITUTION: Each coefficient composed of a process gain, a time constant and an idle time contained in a tension generating process model formula is confirmed, a fluctuation range of an actual coefficient is obtained and the maximum error is expressed by an adequate frequency weight filter from the basic model expressed by a confirmed coefficient in each frequency. Coefficients n0-n, d1-d of a controller are obtained by applying the H∞ control theory to the frequency weight filter, a mill motor speed correction quantity ΔviREF is calculated by the formula to obtain peripheral speed corrections of the rolls 2, 3 of a rolling mill by using a tension deviation being a difference between a tension target value from (m) samples before this coefficient to the present and a measured value of tension and the mill motor speed correction of one sample before (m) samples.