The mission Fermi / GLAST is part of the NASA program on the study of the Structure and Evolution of the Universe and the fundamental physics research program without accelerators DOE (USA). The mission is supported by physics and astrophysics programs in many partner countries such as France, Germany, Italy, Japan and Sweden. The GLAST observatory consists of two instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM) that will map the cosmos from an energy of about 10 keV to hundreds of GeV; Such high values of energy have never been achieved so far.