PURPOSE: To make the driving unit inexpensive, and to make the low rolling load possible to perform the rolling work for the wide breadth, by first performing the rolling work while keeping constant the circumferential speed ratio between upper and lower work rolls, and next, by changing respective work roll's circumferential speed from each other, and by performing the rolling work while the staged change is given to the circumferential speed ratio.

CONSTITUTION: In the rolling apparatus possessing the driving unit which is provided with gears 7W12 for connecting mechanically the isodiametric upper and lower work rolls 1, 2, at the driving system of these rolls 1, 2, the motor 6 is driven under the condition that the gears 8 and 11, for example, are being engaged to be stationary; hereby, the rolls 1, 2, are rotated. The rolls 1, 2, are rotated at different circumferential speeds and at a constant circumferential speed ratio. By rolling the sheet with such fixed circumferential speed ratio, the low rolling load can perform the rolling work, and besides, a high draft percentage is also applicable. Next, by changing the combination of gears 7W9 and gears 10W12, the respective circumferential speeds and their ratio of the rolls 1, 2, are changed. By giving the staged change to the draft percentage by successively combining the suitable diameteric gears to engage, the rolling work convering the wide range of breadth can be performed eventually.