A transparent substrate provided with a stack of thin layers includes an alternation of n functional layers having reflection properties in the infrared region and/or in solar radiation with n≧2 and of n+1 coatings including one or more dielectric layers, so that each functional layer is positioned between two coatings, the coatings and the functional layers are numbered according to their position with respect to the transparent substrate, the lower coating 1 is placed above the transparent substrate and below the functional layer 1, the intermediate coatings 2 to n are placed between two functional layers and the upper coating n+1 is placed above the functional layer n, wherein at least one of the upper or intermediate coatings 2 to n+1 includes at least one barrier coating including at least two barrier layers, one layer including silicon and one layer based on aluminum nitride.