  We report on the {\it Chandra} discovery of large scale non--thermal emission
features in the double lobed SSRL quasar 3C 207 (z=0.684). These are: a diffuse
emission well correlated with the western radio lobe, a bright one sided jet
whose structure coincides with that of the eastern radio jet and an X-ray
source at the tip of the jet coincident with the hot spot of the eastern lobe.
The diffuse X-ray structure is best interpreted as inverse Compton (IC)
scattering of the IR photons from the nuclear source and provides direct
observational support to an earlier conjecture (Brunetti et al., 1997) that the
spectrum of the relativistic electrons in the lobes of radio galaxies extends
to much lower energies than those involved in the synchrotron radio emission.
The X-ray luminous and spatially resolved knot along the jet is of particular
interest: by combining VLA and {\it Chandra} data we show that a SSC model is
ruled out, while the X-ray spectrum and flux can be accounted for by the IC
scattering of the CMB photons (EIC) under the assumptions of a relatively
strong boosting and of an energy distribution of the relativistic electrons as
that expected from shock acceleration mechanisms. The X-ray properties of the
hot spot are consistent with a SSC model. In all cases we find that the
inferred magnetic field strength are lower, but close to the equipartition
values. The constraints on the energy distribution of the relativistic
electrons, imposed by the X-ray spectra of the observed features, are
discussed. To this aim we derive in the Appendices precise semi--analytic
formulae for the emissivities due to the SSC and EIC processes.
