It is an object of the present invention to provide a novel method for producing a fluoropolymer according to which unstable terminal groups can be sufficiently stabilized under mild conditions. This invention is related to a method for producing a stabilized fluoropolymer comprising subjecting a fluoropolymer to be treated containing no —SO2X (X representing F or Cl) group-containing monomer units to the following step A, step B and step C in that order: A: Step of reacting with a halogenating agent; B: Step of reacting with a degradation treatment agent; C: Step of reacting with a fluorinating agent.