High resolution Fourier transform spectra of the atmosphere in the 2850 ‐ 2950 cm−1region have been recorded from the ground using the sun as a source. For the first time, many NO2absorption peaks belonging to the ν1+ ν3band and its associated hot band ν1+ ν2+ ν3− ν2have been located. Among them, 13 well isolated features have been used to determine NO2vertical column densities. Indeed, from the analysis of 4 spectra recorded at air masses of 10.7, 5.4, 3.1 and 10.8, that is for the 3 first ones just after sunrise and in the early morning and for the last one just before sunset, vertical column densities of 1.84 ± 0.34, 1.80 ± 0.28, 1.74 ± 0.44 and 3.24 ± 0.46 1015molecule.cm−2have been obtained. The good absolute accuracy of these results is due to the use of several lines having a wide enough range of intensities and of lower st