NOVELTY - Dinitrogen tetroxide absorbing involves passing dinitrogen tetroxide gas with dilute nitric acid and hydrogen peroxide through a two-stage combination system, where molar content of dinitrogen tetroxide gas is 20-70%. The obtained mixture of exhaust gases are entered into the absorber with potassium hydroxide (caustic potash). The dinitrogen tetroxide gas is passed into the absorption column at a pressure of 0.02-0.2 magapascal, where flow rate is 100-200 normal cubic meter per hour, and concentration of dilute nitric acid and hydrogen peroxide solution is 3-5% and 0.1- 2%, respectively.    USE - Method for absorbing dinitrogen tetroxide gas from waste gas (claimed).    ADVANTAGE - The method is eco-friendly, cost-effective, combines the absorption of dinitrogen tetroxide gas, and reduces discharge of toxic acidic gas.    DETAILED DESCRIPTION - Dinitrogen tetroxide absorbing involves passing dinitrogen tetroxide gas with dilute nitric acid and hydrogen peroxide through a two-stage combination system, where molar content of dinitrogen tetroxide gas is 20-70%. The obtained mixture of exhaust gases are entered into the absorber with potassium hydroxide (caustic potash). The dinitrogen tetroxide gas is passed into the absorption column at a pressure of 0.02-0.2 magapascal, where flow rate is 100-200 normal cubic meter per hour, and initial concentration of dilute nitric acid and hydrogen peroxide solution is 3-5% and 0.1- 2%, respectively. The combined solution of hydrogen peroxide and dilute nitric acid is oxidized, and then absorbed, where weight percent concentration of nitric acid is 15-20%. An exhaust gas is entered into latter absorber, where initial concentration of dilute nitric acid and hydrogen peroxide solution is 3-5% and 0.1-2%. The combined solution of hydrogen peroxide and dilute nitric acid is oxidized, and then absorbed, where weight percent concentration of nitric acid is 15-20%. The exhaust gases are entered into third absorber, where initial concentration of potassium hydroxide is 16-20%. Nitrogen dioxide in the exhaust gas is converted to a solution of potassium nitrate and nitric oxide is converted to potassium nitrite, where flow rate of absorb liquid in each absorber is 12-13 cubic meter per hour.