Divalent iron ion-containing aqueous solution

The present invention can suppress the oxidation of trivalent iron ions due to aging of the divalent iron ions in an aqueous solution containing divalent iron ions, to prevent long-term generation of precipitation of iron hydroxide (III) aims to storage stability can provide ferrous ion containing aqueous solution with improved. Ferrous ion-containing aqueous solution of the present invention, a divalent iron ion, comprising the hydroxylamine salt as a reducing agent, and ferrous ion storage stability is improved, wherein the pH is 3.0 or less it is an aqueous solution containing. pH is preferably 2.2 or less, more preferably 1.2 or less.