A polymer comprising recurring units of formulae (1), (2), (3) and (4) increases a dissolution rate in an alkali developer under the action of an acid. ##STR00001## R.sup.1, R.sup.2, R.sup.3 and R.sup.6 are H or CH.sub.3, R.sup.4 and R.sup.5 are H or OH, X is a tertiary exo-alkyl group having a bicyclo[2.2.1]heptane framework, represented by any of formulae (X-1) to (X-4): ##STR00002## wherein R.sup.7 is C.sub.1 C.sub.10 alkyl, and Y is a tertiary alkyl group having an adamantane structure. A resist composition comprising the inventive polymer has a sensitivity to high-energy radiation, improved resolution and minimized proximity bias and lends itself to micropatterning with electron beams or deep UV for VLSI fabrication.