Impurities can be removed from a polyphenylene sulfide resin with a high efficiency by heat-mixing a powdery phenylene sulfide resin with a solvent selected from (I) at least one solvent selected from dimethylsulfoxide, sulfolane, glycerol, ethylene glycol and diethylene glycol, (II) a mixed solvent of a solvent selected from dimethylsulfoxide, sulfolane, glycerol, ethylene glycol and diethylene glycol with an .alpha.-halogenated naphthalene or biphenyl, (III) a mixed solvent of the mixed solvent (II) or at least one solvent selected from benzyl alcohol, sulfolane and glycerol with N-methyl-2-pyrrolidone with water to bring the powder and the solvent sufficiently into contact with each other in the partially dissolved state, cooling and filtering the mixture, and washing the filter cake with a solvent incapable of dissolving the polyphenylene sulfide resin therein.