PURPOSE: To execute a fine adjustment of a crown by sliding tapered parts of a upper and the lower work rolls, and allowing the upper and the lower work rolls to ascend and descend, respectively so as to directly bend.

CONSTITUTION: At the time of rolling, thrust force generated in the upper and the lower work rolls 1, 11, respectively is supported by the upper and the lower thrust receiving rolls 2, 12. In this state, one thrust receiving roll of the upper and the lowerthrust receiving rolls is moved in the roll axis center direction by a roll moving means, only one work roll is shifted, or by moving the upper thrust receiving roller 2 and the lower thrust receiving roller 12 in the direction opposite to the roll axis center direction, respectively, the upper and the lower work rolls 1, 11 are shifted in the directions opposite to each other, and tapered parts 11a, 11b of the upper and the lower work rolls are allowed to slide mutually in the axial direction. The rolls are allowed to ascend and descend thereby, respectively, and by utilizing the force of a crown from a reinforcing roll supported so as to be pressable by each roll surface, and an intermediate roll, and bringing the upper and the lower work rolls 1, 11 to direct bending, its crown is brought to fine adjustment, and a plate shape of a rolled stock W is controlled.