Abstract: A photomask material which has high-definition image reproducibility and gives a photomask having good image strength, heat resistance and durability against light (ultraviolet light) and which is for use to form a circuit pattern etc., and a method of effectively processing the above photomask material. The photomask material comprises has at least a silver halide emulsion layer and a physical development center layer on a glass substrate, the physical development center layer being formed between the glass substrate and the silver halide emulsion layer, and gives a photomask having a metal silver image having a thickness of 1 &mgr;m or less formed on the glass substrate and having a maximum optical density of at least 1.