PURPOSE: To start the titled device by a single control system by controlling a looper position after generating a looper raising command and raising the looper conformingly to a predetermined function when the rolling-interstand tension of a rolling material is controlled by mill motor, looper driving systems.

CONSTITUTION: The tension of a rolling material 5 between rolling mills located at the upstream and downstream sides, is feedback controlled by a mill-motor 2 driving system and also by a looper-motor driving system. Here, a looper raising command is given and a looper position is controlled at the same time, to raise the looper from its lower limit at the rate of an increment δ1 conforming to a predetermined function F1. The increase of a reference θref is stopped at the time when the looper comes into contact with the material 5 and the detected tension value σ of a detector 7 exceeds a fixed value , and said reference θref is changed from a present value to a set value θS fixed by a rolling schedule at the rate of an increment δ2 conforming to a predetermined function F2. Further, a tension control is performed when the value σ exceeds the value to the looper tension exceeds a predetermined value.