To obtain a radiation sensitive resist composition extremely suppressing the deposition of a crystalline extraneous material based on the radiation sensitive compound and the generation of fine solid particle generated in storage, by preparing the concentration of the alkali soluble resin lower than the prescribed value.

This composition is obtained by containing (A) an alkali soluble resin (preferably; novolac resin), (B) a radiation sensitive compound (preferably; 1,2-naphthoquinonediazide compound) and (C) a solvent and preparing the composition having the concentration of the component (A) lower than the prescribed concentration in the first stage, and adding component (A) to the prescribed concentration in the second stage. Between the first stage and the second stage the composition is filtered, and the component (A) is, preferably, added by using the solution of component (A) in the second stage.