PURPOSE: To easily and quickly exchange a roll by providing an angular trunnion in one end of a working roll, providing a circular trunnion in the other end and supporting them in a clamp which is formed by dividing.

CONSTITUTION: An angular trunnion 1.1 is provided in one end of a working roll 1 and a circular trunnion 1.2 is provided in the other end. The angular trunnion 1.1 is supported in a clamp which is divided and formed by a fixed clamp part 2.1 and a movable clamp part 2.2 in a driving shaft 2. The circular trunnion 1.2 is supported in the clamp which is divided and formed by the fixed clamp part 3.1 and the movable clamp part 3.2 in a supporting trunnion 3. The working roll 1 is attached to the driving shaft 2 and into the divided clamp of the supporting trunnion 3 which is also served as a guide, respectively. The roll 1 is removed by loosening a screw 4 of the divided clamp and by turning the movable clamp parts 2.2, 3.2 around a bolt 6 as the center or the like.