To reduce upward camber and downward camber which are generated during and after the time of rolling by displacing the upper and lower work rolls of a roughing mill in the horizontal direction to the entering side and exiting side of a rolled stock.

In the control method of this device for displacing the work rolls of the roughing mill in the horizontal direction and the rolling mill using this device, the amount of displacement in the horizontal direction of the upper and lower work rolls 5-1, 5-2 is determined from pick-up angles obtained from information which the thickness of the rolled stock 10 is measured with sensors 7 (7-1, 7-2, 7-3) for measuring thickness and rolling is executed in a state where each work roll 5-1, 5-2 is displaced (offset). In this way, the upward camber and downward camber are prevented.