Acetal compounds in which a 5- or 6-membered ring acetal structure is connected to a norbornene structure through a linker represented by —(CH₂)_m— in which one hydrogen atom may be substituted with a hydroxyl or acetoxy group, and m is from 1 to 8 are novel. Using the acetal compounds as a monomer, polymers are obtained. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation and has excellent sensitivity, resolution, and etching resistance.