Process for producing polyarylene sulfide

A process for polyarylene sulfide production in which polyarylene sulfide particles cleaned are recovered from a polymer slurry which has been obtained by reacting an alkali sulfide source with a dihalogenated aromatic compound in a polar organic solvent and comprises polyarylene sulfide particles, fine alkali metal salt particles generated as a by-product, and the polar organic solvent, the process comprising separating the polymer slurry into the polyarylene sulfide particles and a slurry containing the fine alkali metal salt particles by sieving, introducing the separated polyarylene sulfide particles into a countercurrent cleaning apparatus with a built-in movable part, and subjecting the particles to a cleaning step in which the particles are continuously contacted countercurrently with a cleaning fluid. A satisfactory-quality product of polyarylene sulfide particles can be obtained in a satisfactory yield while pursing process rationality.