The results obtained in the studies suggest the conclusion that the thermal desorption spectroscopy technique can be related to the methods enabling the estimation of the structural state of materials. The present paper reports the results from studies (hydrogen diagnostics) of structural states of materials, using 18Cr10NiTi steel as an example, the structure of which has been subjected to various actions such as reactive-element ion (N(+), O(+)) implantation, cold extrusion deformation. The present results indicate that the use of thermodesorption spectrometry of hydrogen holds promise for estimating the structural condition of the metal and its changes under various actions. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.