METHOD FOR OBTAINING OF PRINTING PLATE ACCORDING TO SILVER SALT DIFFUSION TRANSFER PROCESS

PROBLEM TO BE SOLVED: To provide a method of manufacturing a printing plate storable without substantially impairing printing properties such as printing resistance and ink receptivity in a shortened dipping time in a developer, according to a silver salt diffusion transfer process. SOLUTION: A method of manufacturing a lithographic plate according to a silver salt diffusion transfer process using photographic material includes a process of exposing photographic material, containing a silver halide emulsion layer and a physical developing nucleus contained layer on a support body, according to an image, a process of leading the photographic material exposed according to the image, into an alkaline processing solution containing a hydrophobic agent for 15 seconds or less to develop the photographic material, and a process of leading the developed photographic material into a stabilizing solution. In this case, the stabilizing solution contains a mercapto group contained compound with pKa of 4.5 or less.