The authors elaborated a method measuring air level of orthophosphorous and orthophosphoric acids by means of ion chromatography within the range of 0.1-25 mg/cu m. The samples are extracted through concentration on a filter. The analysis regime includes depression of the background levels. The separating column (4 x 200 mm) is filled with anion exchanger BT IAN, the suppressing column (6 x 150 mm) is filled with cation exchanger Dowex 50 x 8, the elutriating agent is 1.5 mM of sodium carbonate, the detector is conductometric. Minimal amounts of ions that could be detected in the analyzed solution are 7-10 ng (HPO32-), 10-15 ng (HPO 42-). The method is designed to analyze the air of workplace.