PURPOSE: To form a resist pattern of high sensitivity and of high resolution by using a mixture of a polysiloxane incorporating Si-O bonds in the main chain and a polysulfone decomposable by irradiation, with charged particle beams.

CONSTITUTION: This pattern forming material is a mixture of the polysilicone resin of high dry etching resistance having Si-O bonds in the main chain and the polysulfone resin decomposable with the irradiation of electron beams. Thus since it incorporates silicone atoms of high dry etching resistance, no shift of the measurements at a pattern transfer occurs, and the resist processing step is simplified, and it has high sensitivity, and since the alkaline aqueous solution can be used as a developer, a resist pattern with wide tolerance in processing and of exactness and fineness is formed.