PURPOSE: To improve working efficiency by measuring the delivery speed of a material to be rolled or a material to be straightened on the outlet side of a rolling mill or a straightening machine and executing feed-back or setup of the measured value to the number of revolution of the rolling mill or the straightening machine and the number of revolution of a table roller.

CONSTITUTION: The speed of the steel material 6 to be straightened delivered from the straightening machine 7 is measured with a speedometer 4 provided on the outlet side of the straightening machine 7. The measured value is inputted to a computer 5 and, based on the measured delivery speed, the exact number of revolution of a straightening roll 8 and the numbers of revolution of the table roller 1 on the inlet side and table roller 3 on the outlet side are calculated using an equation stored in the computer 5. Those calculated results are set up before the next steel material gets on the table roller 1 on the inlet side and straightening is executed by those values. In this way, rolling or straightening work is smoothly at the delivery speed as set and working efficiency is improved.