Novel ester compounds having formula (1) wherein A.sup.1 is a polymerizable functional group having a double bond, A.sup.2 is furandiyl, tetrahydrofurandiyl or oxanorbornanediyl, R.sup.1 and R.sup.2 each are a monovalent hydrocarbon group, or R.sup.1 and R.sup.2 may bond together to form an aliphatic hydrocarbon ring with the carbon atom, and R.sup.3 is hydrogen or a monovalent hydrocarbon group which may contain a hetero atom are polymerizable into polymers. Resist compositions comprising the polymers are sensitive to high-energy radiation, have an improved sensitivity, resolution, and etching resistance, and lend themselves to micropatterning with electron beams or deep-UV rays. ##STR00001##