The excitation of odd sextet levels of the niobium atom in collisions with
slow electrons is investigated experimentally. The measured values of the e
xcitation cross sections of the spectral lines of NbI are used to determine
the excitation cross sections of energy levels. The available reference da
ta on the branching factors are used for more complete inclusion of branchi
ng. The obtained values of excitation cross sections of the levels of the n
iobium atom are compared with the theoretical values.