PLANOGRAPHIC PRINTING PLATE

PROBLEM TO BE SOLVED: To obtain a planographic printing plate using a silver complex salt diffusion transfer process and having improved water retentivity by incorporating a matting agent comprising a zirconium compound into at least one of an undercoat layer and a silver halide emulsion layer. SOLUTION: The planographic printing plate has at least an undercoat layer, a silver halide emulsion layer and a physical developing nucleus layer on the substrate and contains a matting agent comprising a zirconium compound in at least one of the undercoat layer and the silver halide emulsion layer. The zirconium compound is, e.g. zirconium oxide, zirconium phosphate, zirconium silicate, zirconium hydroxide or zirconium oxychloride. The zirconium matting agent is used in the undercoat layer and/or the silver halide emulsion layer, preferably in the silver halide emulsion layer. The content of the zirconium matting agent is appropriately adjusted to the amount of gelatin in the layer in which the zirconium matting agent is contained.