XTE J1118+480 is a well established black hole candidate with a mass estimate in the range from 7 to 10 solar masses .
With BeppoSAX we observed the source 4 times , from April to December 2000 .
Results of the first observation were already reported ( Frontera et al .
2001 ) .
Here we report spectral results of the later observations , performed in May , June and December 2000 and compare them with the results obtained from the 2000 April observation .
We observe a decrease of the column density from a value consistent with the Galactic N _ { H } ^ { G } obtained from radio measurements to a value a factor 2 lower .
The spectra are well fit with a thermal Comptonization plus a blackbody model .
The blackbody luminosity decreases with time , while the electron temperature of the Comptonizing electrons does not show significant changes .
A Compton reflection component is apparent and stable , although weak ( mean value of \Omega / 2 \pi = 0.21 ^ { +0.05 } _ { -0.04 } ) .
The reflector shows a low metallicity ( mean value of Z / Z _ { \odot } = 0.13 ^ { +0.06 } _ { -0.04 } ) .
On the basis of the spectral results , a hot central disk appears the best scenario for the high energy photons , while the temporal properties point to a non thermal origin of a fraction of the soft X–ray photons , likely synchrotron emission internal to the hot disk .