An alkali metal fluoride dispersion essentially consisting of an alkali metal fluoride and an aprotic organic solvent obtainable by conducting the following Step (A), subsequently conducting the following Step (B) at least once, and then conducting the following Step(C); Step (A) : a step of separating a liquid phase from an alkali metal fluoride dispersion comprising at least one alcohol solvent selected from the group consisting of methanol, ethanol and isopropanol and an alkali metal fluoride, and mixing the separated liquid phase with an aprotic organic solvent having a boiling point of 85°C or higher at normal pressure to obtain a mixture containing the alkali metal fluoride; Step (B) : a step of obtaining a mixture containing the alkali metal fluoride comprising the following Steps (b1) to (b3); Step (b1) : a step of concentrating the mixture containing the alkali metal fluoride obtained in Step (A) or Step (b3) to obtain a concentrated fraction and a concentrated residue; Step (b2) : a step of mixing a residue of the alkali metal fluoride dispersion obtained by separating the liquid phase in Step (A) or a residue of the mixture obtained by separating a liquid phase in Step (b3) with the concentrated fraction obtained in Step (b1) to obtain a mixture containing an alkali metal fluoride; and Step (b3) : a step of separating a liquid phase from the mixture containing an alkali metal fluoride obtained in Step (b2) and mixing the separated liquid phase with the concentrated residue obtained in Step (b1) to obtain a mixture containing an alkali metal fluoride; and Step (C) : a step of removing the alcohol solvent fromthemixture containing the alkali metal fluoride, which is obtained in Step (B), to obtain the alkali metal fluoride dispersion essentially consisting of the alkali metal fluoride and the aprotic organic solvent.