To provide an equipment which attenuates vibration to be often occurred when the thickness of a roll is drastically reduced, wherein almost equal friction condition is generated between a band surface of a rolled stock and an upper roll, a band lower face of a rolled stock and a lower roll, and thereby an efficiency of rolling process is improved and an abrasion of the upper roll and the lower roll is reduced.

This equipment 1 which adjusts the friction condition of an upper roll 6 and a lower roll 7 of a rolling stand 28 of a hot wide band material rolling mill or a cold band material rolling mill, consists of a spray device 2 which is installed at the entrance 27 of the rolling stand 28 and sprays the liquid of the fixed quantity to the roll clearance and a control equipment 3 for deciding the quantity of this liquid and discharging. The quantity decided or calculated beforehand is used as the control quantity in connection with the measured value of an actual roll torque of the lower roll 7 and/or the upper roll 6.