To make it easy to perform the fabrication, and securely fix a printing plate to a plate cylinder and detach the printing plate from the plate cylinder face.

In a printing machine for printing data with a printing plate mounted on a plate cylinder 1, it has a slit 11 provided on the plate cylinder 1 in such a manner that it is inclined in the radial direction of the plate cylinder 1 and set in parallel with the axial line of the plate cylinder 1, and small holes 12, 12,... opened on a plate cylinder face at a position close to the slot 11 on the side forming an obtuse angle tangentially with the contour of the plate cylinder face and along the slot 11. In addition, the upstream side of the slit 11 is connected to an air suction source and an air vent source, while the downstream side is confluent communication with the small holes. Further, the printing machine is structurally equipped with an air ventilation duct 2 for enabling the air to be sucked and vented through the opening parts of the small holes, and a switching means 3 for switching the air suction and the air vent process through the opening parts of the small holes 12, 12,..., provided in the air ventilation duct 2.