PURPOSE: To reduce the moment load of a frame by making a pitch between straightening rolls, arranged respectively in zigzag at the upper and lower sides of a work, adjustable and making stands, which receive a load by connecting upper and lower frames, movable.

CONSTITUTION: In a straightening machine, whose upper straightening rolls 1W4 and lower straightening rolls 5W7 are arranged respectively in zigzag at the upper and lower sides of a work 27 by making a pitch between the straightening rolls adjustable; the upper and lower frames 8 and 9 of the machine are connected to each other and fixed in the vertical direction by stands 10, 11, which receive a straightening load and are formed to be movable on the frames 8, 9 in the advancing direction of the work 27. By this construction, the distance between the stands is made minimum in accordance with the size of a product, and a bending moment produced in the upper and lower frames by a straightening load is made small.