The effect of ascorbic acid concentration on the absorption of NO(2) into an aqueous ascorbic acid solution was investigated experimentally. A gas mixture that includes nitrogen dioxide was passed through a bubble column type batch absorption apparatus, and concentrations of nitrite and nitrate in the liquid absorbent were measured. With an aqueous ascorbic acid solution, nitrite can be selectively produced and production of nitrate can be inhibited. When ascorbic acid was used as reductant, an active oxygen removal capacity comparable to that of the sulfite absorbent was observed at about 1/10 of the sulfite concentration.