  The ANTARES neutrino telescope detects the Cherenkov radiation emitted along
the path of charged particles produced in neutrino interactions. ANTARES is
sensitive to all flavors even though it is optimized for muon neutrinos.
Several algorithms estimating the deposited energy in the active volume of the
detector have been developed and applied to the reconstruction of the primary
neutrino energy - this allows to improve the search for a diffuse flux of
astrophysical neutrinos. The search for a diffuse flux of cosmic neutrinos at
very high energies (E_\nu > 30 TeV) is updated using 4 years of data with the
full detector.
