A sulphur-containing and sulphonated aromatic perfluoroalkane monomer is provided that can be used for the manufacture of a polymer membrane for a PEM-type fuel cell. The perfluoroalkane monomer is a functionalized polymer that has a structure corresponding to a formula (I): E1-Ar1—X1—(CF2)n—X2—Ar2-E2  (I) in which: n is in a range from 1 to 20; X1 and X2, which are identical or different, represent S, SO, or SO2; Ar1, Ar2, which are identical or different, represent a phenylene group, at least one of Ar1 and Ar2 bearing a sulphonic (—SO3H) group or a sulphonate (—SO3M) group, in which M represents an alkali metal cation; and E1 and E2, which are identical or different, represent an electrophilic group such as a halogen, specifically fluorine or chlorine.