A method of manufacturing granular PAS according to the present invention includes: a polymerizing step of subjecting a dihalo aromatic compound and at least one type of sulfur source selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides to polymerization reaction in an organic amide solvent; and a cooling step of cooling the reaction product mixture after the polymerizing step. Addition of a phase separation agent to the reaction product mixture is started at a point in time from the start of the polymerizing step to before the start of forming granular PAS in the cooling step, and when the temperature of the reaction product mixture is 245° C. or higher, 50 mass % or greater of the phase separation agent is added to the reaction product mixture. The polymerizing step includes a predetermined PAS prepolymer generating step, and a predetermined converting step to a high molecular weight PAS.