The invention relates to a substrate (10), such as a transparent glass substrate, which is equipped with a stack of thin layers comprising an alternating stack of n functional layers (40) having reflection properties in the infrared and/or solar radiation range, particularly metal functional layers based on silver or metal alloy containing silver, and (n+1) dielectric coatings (20, 60), wherein n = 1, said coatings being formed by one or more layers (22, 24, 62, 64) of which at least one is made from a dielectric material, such that each functional layer (40) is disposed between at least two dielectric coatings (20, 60). The invention is characterised in that at least one functional layer (40) comprises a blocking coating (30, 50) consisting of at least one interface layer (32, 52) which is in direct contact with the functional layer and which is based on titanium oxide TiO x .