Provided is a method for producing a
fluorine-containing
polymer, the method comprising: a step in which a
monomer (I) represented by general formula (I) is polymerized in an
aqueous medium in the absence of a
fluorine-containing surfactant (excluding the
monomer (I) represented by general formula (I)) substantially, thereby obtaining a crude composition of a
polymer containing the
monomer (I); a step for obtaining a
polymer (I) in which the content of the
dimer and the
trimer of the monomer (I) is 1.0
mass% or less relative to the polymer (I) by removing the
dimer and the
trimer of the monomer (I) contained in the crude composition from the crude composition; and a step for obtaining a
fluorine-containing polymer by polymerizing a fluorine-containing monomer in an
aqueous medium in the presence of the polymer (I). CX1X3 = CX2R (-CZ1Z2-A0) m (I) (In the formula, X1 and X3 are each independently F, Cl, H, or CF3; x2 is H, F,
alkyl or fluorine-containing
alkyl; a0 is an anionic group; r is a linking group; z1 and Z2 are each independently H, F,
alkyl or fluorine-containing alkyl; and m is an integer of 1 or more. ).