PURPOSE: To move a plate to a predetermined position within a short time by simplify the operation for adjusting the mounting position of the plate and quickly and certainly moving a second grasping mechanism when the operation is performed.

CONSTITUTION: A printing press is equipped with a plate cylinder 7 an first and second plate lock-up devices 17, 18. The plate lock-up device 17 is attached to the attaching groove 16 provided to the outer periphery of the plate cylinder 7 in a shakable manner by bolt 33 to grasp the first end part 8a of a plate 8. The plate lock-up device 18 is provided to the attaching groove 16 so as to be movable in the direction conforming to the axial line L of th plate cylinder 7 and the first end part 8a of the plate 8 is grasped by the plate lock-up device 17 and the second end part 8b of the plate 8 held to the state wound around the outer periphery of the plate cylinder 7 is grasped by the plate lock-up device 18. When the plate 8 grasped by both plate lock-up devices 17, 18 is shifted from a predetermined position, an adjusting screw 61 is screwed in one end of the plate lock-up device 18 in order to forcibly move the plate lock-up device 18 along the axial line L to move the plate 8 to the predetermined position. A connection mechanism connecting the adjusting screw 61 so as to make the movement thereof along the axial line L of the plate cylinder 7 impossible is provided.