Formation of negative ions initiated by interaction of thermal electrons and in the corona discharge (CD) in N2 with small admixture of SF6; was studied using the ion mobility spectrometry- orthogonal acceleration time-of-flight mass spectrometry (IMS-oaTOF) at atmospheric pressure. The negative ions have been analyzed by the ion mobility spectrometry and mass spectrometry (IMS-MS) and two-dimensional spectra (2D IMS-MS) have been recorded. We discuss the mechanisms of the negative ion formation in the N2/SF6 mixtures (0.003-0.018%) as well as the transport parameters of the ions in these mixtures. The values of the reduced ion mobilities of negative ions formed in these mixtures were determined (2.43 cm2/V s for HF2– (HF)n, 2.32 cm2/V s for NO3– (HF)n, 2.08 cm2/V s for SF5–, 2.01 cm2/V s for SOF5–, 2.00 for SOF4– 1.99 cm2/V s for SF6–, 1.83 cm2/V s for SOF5–(H2O)n and 1.73 for SOF5–(H2O)n(HF)m). The assignment of the ion mobility peaks was performed on the basis of the 2D IMS-MS spectra.