PURPOSE: To control a rolling with high accuracy without subjecting to an effect of hysteresis in a mill rigidity, by measuring a rolling load and controlling it with strain gauges provided to the specific positions of the housing where a bad effect of a rolling mill itself is avoided.

CONSTITUTION: Strain gauges 8 are set to the positions (c) at which center lines (a) of a housing and a passing line (b) intersect with each other. Each one strain gauges 8 is distributed to each post 5 and four sets in total. A rolling control with an excellent accuracy is performed by automatically controlling the sheet thickness, using the measured values of the gauges 8 as the one of the controlling factors.