To provide a fluoropolymer having functional groups and having high transparency in a wide wavelength range, and a resist composition and a composition for a resist protective film, comprising the fluoropolymer. A fluoropolymer having monomer units formed by cyclopolymerization of a fluorinated diene represented by the formula (1): CF2═CFCF2C(CF3)(OR1)—(CH2)nCR2═CHR3  (1) wherein R1 is a hydrogen atom, an alkyl group having at most 20 carbon atoms, or (CH2)aCOOR4 (wherein a is 0 or 1, and R4 is a hydrogen atom or an alkyl group having at most 20 carbon atoms), each of R2 and R3, which are independent of each other, is a hydrogen atom or an alkyl group having at most 12 carbon atoms, and n is 0 or 2, provided that when n is 0, at least one of R1, R2 and R3 is other than a hydrogen atom.