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):CF.sub.2.dbd.CFCF.sub.2C(CF.sub.3)(OR.sup.1)--(CH.sub.2).sub.nCR.sup.- 2.dbd.CHR.sup.3 (1)wherein R.sup.1 is a hydrogen atom, an alkyl group having at most 20 carbon atoms, or (CH.sub.2).sub.aCOOR.sup.4 (wherein a is 0 or 1, and R.sup.4 is a hydrogen atom or an alkyl group having at most 20 carbon atoms), each of R.sup.2 and R.sup.3, 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 R.sup.1, R.sup.2 and R.sup.3 is other than a hydrogen atom.