  A BeppoSAX observation of the BLRG 3C390.3 is reported. For the first time,
both the 6.4 keV iron line and a strong reflection hump, produced by the
illumination of the primary X-ray emission on cold matter, are detected in this
source. The 0.1-100 keV continuum is modeled by an absorbed power law (\Gamma~
1.8) reflected at high energies by material with a fairly large covering factor
(\Omega/2\pi~1). The iron line is intrinsically narrow ($\sigma=73(+207,-73)
eV) and has an equivalent width of ~140$ eV. We discuss the results in the
context of current models for AGNs and suggest that the primary X-ray power law
continuum is probably produced by a hot inner flow, while the reprocessed
radiation comes from an outer cold thin disk, and/or from a thick torus at even
larger radii. Further observations with BeppoSAX could distinguish between the
latter two cases. Beamed radiation associated to the radio jet is unlikely to
contribute significantly to the X-ray emission. Finally, an historical study of
the column density NH, also reported here, shows that the absorption along the
line of sight changes in time. The NH time variability, which is not correlated
with that of the primary continuum, seems to imply variations of the geometry
of the absorber rather than variations in the ionization state of the gas.
