Abstract: A radiation sensitive resist composition with high sensitivity, capable of forming a highly heat-resistant resist pattern. The radiation-sensitive resist composition contains, together with a resist material, a polymer which is obtained by reacting (a) a xylylene compound, (b) salicylic acid and (c) 9,9'-bis(hydroxyphenyl)fluorene derivatives or diol compounds of 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene, and which has a weight average molecular weight of 1,000 to 5,000 and Tg of 100 to 150.degree. C. Examples of (c) include 9,9'-bis(4-hydroxyphenyl)fluorene and 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol. As the resist material, any of positive- and negative-working resists may be used, with that comprising an alkali-soluble resin and a quinonediazide photo-sensitizer being preferably used.