METHOD FOR PRODUCING AQUEOUS a-SULFO FATTY ACID ALKYL ESTER SALT SOLUTION

The present invention relates to a method for producing an aqueous α-SF salt solution that maintains fluidity and has superior production adaptability. The method includes dissolving a solid component (a) in the form of an α-sulfo fatty acid alkyl ester salt and a component (b) in the form of an inorganic sodium salt and/or inorganic potassium salt in water, wherein component (a) is dissolved in water at a temperature of 50° C. or higher while maintaining the following condition (i) or (ii): (i): the concentration of component (a) is 35% by weight or less when the total concentration of sodium and potassium ions derived from component (b) is less than 0.55 mol/kg, or (ii) the concentration of component (a) is 55% by weight or less when the total concentration of sodium and potassium ions derived from component (b) is 0.55 mol/kg to less than 1.8 mol/kg.