A method of producing a sulfonic acid group-containing ether compound represented by the following formula: wherein: R 1 represents a single bond, a CH 2 group, or a CH 2 CH 2 group; R 2 represents H, or a CH 3 group; X and Y may be the same as or different from each other and each represents a hydroxy group or a sulfonic acid (salt) group, and at least one of X and Y is a sulfonic acid (salt) group, and the sulfonic acid (salt) group is a group represented by -SO 3 Z wherein Z is a hydrogen atom, metal atom, ammonium group, or organic amine group; by reacting a sulfurous acid compound with a compound represented by the formula: wherein: R 1 represents a single bond, a CH 2 group, or a CH 2 CH 2 group; and R 2 represents H, or a CH 3 group, the method comprising the steps of: adjusting the pH of a reaction system to 5.5 or greater with the use of an alkaline substance, wherein "reaction system" refers to the inside of a reaction vessel; and adding the compound represented by the formula to the reaction vessel containing the sulfurous acid compound, and the addition step is carried out after the pH adjustment step, wherein the reaction between the compound represented by formula and the sulfurous acid compound is carried out at a reaction temperature of 30°C or higher and lower than 80°C. R 1 represents a single bond, a CH 2 group, or a CH 2 CH 2 group; R 2 represents H, or a CH 3 group; X and Y may be the same as or different from each other and each represents a hydroxy group or a sulfonic acid (salt) group, and at least one of X and Y is a sulfonic acid (salt) group, and the sulfonic acid (salt) group is a group represented by -SO 3 Z wherein Z is a hydrogen atom, metal atom, ammonium group, or organic amine group; R 1 represents a single bond, a CH 2 group, or a CH 2 CH 2 group; and R 2 represents H, or a CH 3 group, the method comprising the steps of: adjusting the pH of a reaction system to 5.5 or greater with the use of an alkaline substance, wherein "reaction system" refers to the inside of a reaction vessel; and adding the compound represented by the formula to the reaction vessel containing the sulfurous acid compound, and the addition step is carried out after the pH adjustment step, wherein the reaction between the compound represented by formula and the sulfurous acid compound is carried out at a reaction temperature of 30°C or higher and lower than 80°C. the method comprising the steps of: adjusting the pH of a reaction system to 5.5 or greater with the use of an alkaline substance, wherein "reaction system" refers to the inside of a reaction vessel; and adding the compound represented by the formula to the reaction vessel containing the sulfurous acid compound, and the addition step is carried out after the pH adjustment step, adjusting the pH of a reaction system to 5.5 or greater with the use of an alkaline substance, wherein "reaction system" refers to the inside of a reaction vessel; and adding the compound represented by the formula to the reaction vessel containing the sulfurous acid compound, and the addition step is carried out after the pH adjustment step, wherein the reaction between the compound represented by formula and the sulfurous acid compound is carried out at a reaction temperature of 30°C or higher and lower than 80°C.