The black hole system 1E 1740.7–2942 is usually the brightest hard X-ray source ( above 20 keV ) near the Galactic Center , but presents some epochs of low emission ( below the INTEGRAL detection limit , for example ) . In this work , we present the results of studies on 1E 1740.7–2942 over 10 years , using the instruments ISGRI/IBIS and JEM-X , both on board the INTEGRAL observatory . We fit the spectra with both the compTT and cutoffpl models . According to the fits and taking the mean value over the 10 years , we have obtained a plasma temperature in the range \sim 20–90 keV , and an average powerlaw index of 1.41 ( \sigma =0.25 ) . We have also made a Lomb–Scargle periodogram of the flux in the 50–20 keV band and found two tentative periods at 2.90 and 3.99 days . We present here the preliminary results of this ongoing work .