  A new class of X-ray binaries has been recently discovered by the high energy
observatory, INTEGRAL. It is composed of intrinsically obscured supergiant high
mass X-ray binaries, unveiled by means of multi-wavelength X-ray, optical,
near- and mid-infrared observations, in particular photometric and
spectroscopic observations using ESO facilities. However the fundamental
questions about these intriguing sources, namely their formation, evolution,
and the nature of their environment, are still unsolved. Among them, IGR
J16318-4848 - a compact object orbiting around a supergiant B[e] star - seems
to be one of the most extraordinary celestial sources of our Galaxy. We present
here new ESO/VLT VISIR mid-infrared (MIR) spectroscopic observations of this
source. First, line diagnostics allow us to confirm the presence of absorbing
material (dust and cold gas) enshrouding the whole binary system, and to
characterise the nature of this material. Second, by fitting broadband near to
mid-infrared Spectral Energy Distribution - including ESO NTT/SofI, VLT/VISIR
and Spitzer data - with a phenomenological model for sgB[e] stars, we show that
the star is surrounded by an irradiated rim heated to a temperature of
3800-5500 K, along with a viscous disk component at an inner temperature of 750
K. VISIR data allow us to exclude the spherical geometry for the dust
component. This detailed study will allow us in the future to get better
constraints on the formation and evolution of such rare and short-living high
mass X-ray binary systems in our Galaxy.
