Hydrogen incinerates in most compounds and element due to its small size, so when it is used in oil shale exploitation, it may react with the elements making up the reactor and the steel enclosure forming the exploitation assembly. In this work we will treat an 18-9 stainless steel under the same hydropyrolysis conditions as the Tarfaya oil shale (Morocco) and predict which elements of the steel will not be affected by hydrogen.The advantage of treating oil shale with hydrogen is that it increases the oil yield compared with pyrolysis, and it also makes these oils lighter, as well as forming numerous hydrides with the mineral matrix, which are also fuels.After treating 18-9 stainless steel and using analytical techniques, we selected the elements iron β and nickel, which do not undergo alteration in the presence of hydrogen. The analytical techniques used in this work are thermogravimetry using the Red-Croft balance(A.Attaoui :2022) where we carried out the hydrotreatment, calorimetry (DCA) as an amplified calorimetric differential linked to the balance, morphology carried out by SEM (scanning electron microscope) and which is coupled with dispersive X-rays.