PURPOSE: To save man power, to quicken speed and to reduce cost in the cutting operation of rolling roll by moving and fixing a rolling mill to the side of a rolling line of a rolling floor and machining the rolling roll with a cutting tool while rotating the roll by a rolling motor.

CONSTITUTION: A rolling mill body 5 where the rolling rolls 4a, 4b and a rolling reduction motor 14 are mounted on a frame 13 is clamped to a bed 6 on a rolling line L. Rolling is executed by rotating these rolling rolls 4a, 4b with a rolling motor 1 through a flexible universal joint 3 and a reduction gear 2. When the rolling mill body 5 is repaired, the rolling mill body 5 is moved by a cylinder 9 for drawing the rolling mill to the side of a rolling line L along rails 8 to be clamped to a temporarily mounting bed 10. Then, the rolls 4a, 4b are rotated by the rolling motor 1 through the extended universal joint 3 and a cutting tool assembling body 12 is reciprocated on a rest bar 11 to cut the rolls 4a, 4b.