  We present optical spectroscopic identification of sources identified in the
BeppoSAX MECS fields of the High Energy LLarge Area Survey (HELLAS). In total
62 sources from a sample of 115 brighter than F_{5-10keV}>5x10^{-14} cgs have
been identified. We find a density of 13-21 sources/deg^2 at
F_{5-10keV}>5x10^{-14} cgs, which contribute to 20-30 % of the hard X-ray
background. Evidences are found for type 1 AGN being more absorbed with
increasing redshift or luminosity. The low redshift (z<0.2) ratio of type 2 to
type 1 AGN is 3+/-1.5, in agreement with the unified models for AGN. The
luminosity function of type 1 AGN in the 2-10 keV band is preliminary fitted by
a two-power law function evolving according to a pure luminosity evolution
model: L~(1+z)^{2.2}.
