Abstract: A radiation sensitive composition containing resist materials such as quinonediazido photo active compound and alkali soluble resin, and a mixed solvent comprising (A) 1 to 25% by weight of propylene glycol derivatives as represented by the formula:R.sub.1 --O--CH.sub.2 CH(CH.sub.3)--O--R.sub.2wherein R.sub.1 and R.sub.2 are hydrogen atom, alkyl group having 2 to 5 carbons and acetyl group, and total number of carbons in R.sub.1 and R.sub.2 is less than 8, both the R.sub.1 and R.sub.2 are not hydrogen atom at the same time, and (B) 75 to 99% by weight of at least one kind of solvent selected from propylene glycol monomethyl ether acetate and ethyl lactate. The radiation sensitive composition is used for the manufacturing of semiconductor device and liquid crystal display element. The solvent is safe to human body and the amount of residual solvent in the resist film is small.