To commonly use a press plate by forming a gripper side holder to be brought into contact or released from a slit side inner surface of a long hole in a plate cylinder at the time of rotating a tension bar at the bar, and holding only the gripper side end of the plate by the holder.

The press plate 71 is fixed to a plate cylinder 70 in the state that its gripper side end 71a is sandwiched between a slit side inner surface 72a of a long hole 72 and a gripper side holder 75 and added by a predetermined tension. Since the end 71a is held in a gap 77 between the end 71a of a tension bar 73 and the inner surface 72a of the hole 72, a length of the end 71a from a bending part of the plate 71 to a rear end of the plate 71 can be shortened, and hence attaching and detaching of the plate 71 are facilitated. Thus, the plate can be commonly used for offset printers of both three-cylinder type and two-cylinder type folding roller units, and hence a facility cost of a printing table can be reduced.