  The blazar PKS~2155-304 was the target of a multiwavelength campaign from
June to October 2013 which widely improves our knowledge of its spectral energy
distribution. This campaign involved the NuSTAR satellite (3-79 keV), the Fermi
Large Area Telescope (LAT, 100~MeV-300~GeV) and the High Energy Stereoscopic
System (H.E.S.S.) array phase II (with an energy threshold of few tens of GeV).
While the observations with NuSTAR extend the X-ray spectrum to higher energies
than before, H.E.S.S. phase II, together with the use of the LAT PASS 8,
enhance the coverage of the $\gamma$-ray regime with an unprecedented
precision. In this work, preliminary results from the multi-wavelength analysis
are presented.
