A polymer for resist use is obtainable from a monomer having formula (1) wherein R1 is H, CH3 or CF3, R2 and R3 each are H or a monovalent hydrocarbon group, X1 is a divalent hydrocarbon group, k1=0 or 1, and Z forms a 5 or 6-membered alicyclic ring. A resist composition comprising the polymer is shelf stable and displays a high dissolution contrast, controlled acid diffusion and low roughness during both alkaline development and organic solvent development.