A halogenated aromatic compound, a polyarylene (co)polymer obtained by the polymerization of such a halogenated aromatic compound as a monomer component, and a proton-conductive membrane made of a sulfonation product of such a (co)polymer are disclosed. The halogenated aromatic compound is represented by the following general formula (1bm): wherein As′ independently represent an electron-withdrawing group; Bs′ independently represent an electron-donating atom or divalent group; Xs′ independently represent a chlorine atom, an iodine atom, or a bromine atom; Z represents an aryl group; R1 to R19 may be the same or different and each represents a hydrogen atom, a fluorine atom, an alkyl group, or a fluoroalkyl group; and a and b each represents an integer of 1 to 20.