A study using tunneling spectroscopy of the density of states in the v
icinity of Fermi level has been performed on NbSe3 at low temperature.
The tunneling conductance data reveal an asymmetry with respect to th
e Fermi level and below 4.2 K two minima. These results definitely est
ablish the semimetallic character of NbSe3 at low temperature. Tunneli
ng spectra have been analyzed assuming an anisotropic gap structure, a
nd the transverse coupling energy derived is in good agreement with ba
nd calculations.