PURPOSE: To obtain a high purity hydroxylamine salt solution by separating an anode solution chamber and a cathode solution chamber with an anionic membrane and by feeding an aqueous solution containing an acid and water in the anode solution chamber and an aqueous solution containing a hydroxylamine salt, an acid and water in the cathode solution chamber and supplying a direct current.

CONSTITUTION: An electrolysis cell having two chambers is formed by separating an anode solution chamber containing an anode and a cathode solution chamber containing a cathode by an anionic membrane. An aqueous solution containing an acid and water is fed into the anode solution chamber and an aqueous solution containing hydroxylamine salt, an acid and water is fed into the cathode solution chamber. A direct current is applied to the electrolysis cell for an appropriate time to decrease the acid content of the cathode solution chamber. Consequently, the acid content is decreased and a highly pure hydroxylamine salt solution is recovered from the cathode solution chamber.