An object of the present disclosure is to provide a composition comprising a fluorine-containing polymer with high ultraviolet-light permeability, a method for producing a fluorine-containing polymer with high ultraviolet-light permeability, a lens for ultraviolet-light-emitting elements comprising a fluorine-containing polymer with high ultraviolet-light permeability, and the like. Specifically, provided is a composition comprising a fluorine-containing polymer (A), and at least one compound (BC) selected from the group consisting of a polymerization initiator (B) and a decomposed product (C) of the polymerization initiator (B), wherein the compound (BC) is contained in an amount of 0.1 to 100 ppm by mass based on the mass of the composition, and the fluorine-containing polymer (A) comprises as a main component a structural unit represented by formula (A):

##STR00001##

wherein R.sup.1 to R.sup.4 each independently represent a fluorine atom, a C1-C5 perfluoroalkyl group, or a C1-C5 perfluoroalkoxy group.