A novel bisphenol compound comprising an alkylsulfonic acid and/or an alkali metal salt thereof is disclosed. The novel bisphenol compound is preferably represented by the chemical formula shown below. A novel aromatic polyaryl ether synthesized using the bisphenol compound and carrying an alkylsulfonic acid and/or an alkali metal salt thereof in the side chain is also disclosed. (wherein R<5> represents CH3 or a phenyl group; p and q are independently an integer from 1 to 12; and X represents a hydrogen atom or an alkali metal.)
