Abstract <p>Samples of palladium foil with thickness of 1000 and 40 μm obtained at the initial and final stages of cold rolling, respectively, are studied. The influence of the deformation degree in the formation of the substructure and structure was revealed by the studying of hydrogen permeability processes. Electrochemical studies were carried out by cyclic voltammetry and cathodic–anodic chronoamperometry in 0.1 M H₂SO₄ deaerated solution. Different deformation degrees are found not to affect the substructure of the obtained samples, but manifested themselves in surface processes. At the same time, the rate constants of the atomic hydrogen injection and extraction increased. The values of the hydrogen-permeability diffusion parameters for the studied samples confirm that the movement of atomic hydrogen in the solid phase mainly occurs through the crystallite bodies, while the grain boundaries act as trapping defects.</p>