To provide the same plate wear as that of a letterpress printing plate and to obtain the same level of the amt. of ink transfer as that of a gravure printing plate by forming an amorphous plating film with a negative printing plate information on the surface of a copper printing plate material and etching a part with a negative printing plate information except this film and forming a cell for ink storing.

A copper plating 1 is formed by sticking a copper ribbon on a plate roll wherein after the copper surface is mirror surface-abraded, a surface treatment with which the plating is easily peeled off is performed and a photo-sensitive film 5 is formed thereon and a plate information is baked on this photo-sensitive film 5 and is developed to form in such a way that the exposed face 3a of the plate material has a negative plate information and a resist film 8 has a positive plate information. Then, a film 2 consisting of a nickel-phosphorus plating and having a negative plate information is formed on the surface of the copper plating 1. Then, the resist plate information is peeled off to form an offset plate wherein the surface of a printing plate material l is positively exposed and a part with a negative plate information except the plating film is etched to form a cell 4 for storing an ink.