Abstract: To provide a fluoropolymer which has a high concentration of functional groups to provide adequate characteristics of the functional groups and which brings about no decrease of Tg. A fluoropolymer having monomer units formed by cyclopolymerization of a functional group-containing fluorinated diene represented by the formula (1): CFR1?CR2-Q-CR3?CHR4??(1) wherein each of R1 to R4 which are independent of one another, represents a hydrogen atom, a fluorine atom, an alkyl group having at most 8 carbon atoms, or an alicyclic hydrocarbon group, and at least one of them is an alicyclic hydrocarbon group, provided that hydrogen atoms in the alkyl group or the alicyclic hydrocarbon group may be substituted by a fluorine atom, an alkyl group or a fluoroalkyl group; and Q represents a bivalent organic group having a blocked acidic group capable of developing an acidic group by an acid or a group capable of being converted into such a blocked acidic group.