PURPOSE: To suitably reproduce different operating conditions required in tubes, pipes, and industrial products by which simultaneous operation of at least three rollers and adjustment of each of the distances from longitudinal center line of rolling are executed.

CONSTITUTION: A rolling stand 5 is equipped with three driven rollers 27, 28, 29, an external support structure 2a for the driven rollers, and a mechanical power transmission device to transmit power of a driving device to the driven rollers. Furthermore, there are provided a ring-shaped roller support body 10 which is arranged along a center line in the longitudinal direction of rolling, supporting the driven rollers in the inside of radial direction, freely slidable between an operating position and a non-operating position along the center line in the longitudinal direction, is fixed in the inside of the external support structure at the operating position, and excluded from the external support structure at a non-operating position, further a pair of linear guide mechanism 4, 8 to guide moving of the roller support body, and a fixing mechanism B to fix the roller support body to the operating position.