Disclosed is a novel monomer having a lactone skeleton, which is useful typically as a monomer component typically for a highly functional polymer, because, when the monomer is applied typically to a resist resin, the resin is satisfactory stable and resistant typically to chemicals, is highly soluble in organic solvents, and has improved hydrolyzability and/or water solubility after hydrolysis.The monomer having a lactone skeleton is represented by following Formula (1),wherein Ra represents a hydrogen atom, halogen atom, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms; R1 represents a group having a lactone skeleton; and Y represents a bivalent organic group having 1 to 6 carbon atoms.