PURPOSE: To prevent flaw and trouble caused by deflection of rolling material by converting the deflection into speed signal and by controlling a speed at an inlet side of a rolling mill in accordance with the deflection.

CONSTITUTION: The deflection of a rolling material 2 is detected by a deflection sensor 9 equipped near the inlet of rolling mill, and converted into an electrical signal, then outputted to a deflection-speed converter 10. By the converter 10, the deflection signal is converter into the speed signal and a speed compensating signal is outputted. By this compensating signal, an output from a speed setting unit 6 is compensated and the speed of a motor 7 for a conveying table is controlled through a speed reference controlling unit 5. Therefore, even is the deflection of a rolling material 1 is generated at the inlet of rolling mill 2, since the speed of the conveying table 3a is controlled, the deflection is dissolved, and the flaw and trouble caused by the deflection are prevented.