Disclosed is a method for producing a polyphenylene ether, which comprises a step of preparing a polymerization solution composed of 10-25 parts by mass of a phenolic compound (M) and 75-90 parts by mass of an aromatic solvent (A) with the total of the compound and the solvent being 100 parts by mass, and 0.1-10 parts by mass of a catalyst (C) containing a metal salt; a step of performing an oxidative polymerization of the phenolic compound (M) by passing an oxygen-containing gas through the polymerization solution; a step of stopping the polymerization by mixing an aqueous chelating agent solution into the polymerization solution; a step of subjecting a diphenoquinone compound produced as a by-product to a quinone binding process or removal by reduction; and a step of obtaining a polyphenylene ether by separating the aqueous phase through liquid-liquid separation. In the method for producing a polyphenylene ether, 0.001-0.004 part by weight of an ion catalyst (D) is added into the polymerization solution before the liquid-liquid separation.