A thin multilayer coating having reflection properties in the infrared and/or in the solar radiation range of the low-emissivity type for windows comprises a lower dielectric antireflection treatment layer, at least one silver-based functional layer, at least one metallic protection layer adjacent to the silver layer and an upper dielectric antireflection treatment layer. The upper dielectric antireflection treatment layer comprises a lower partial layer made of SnO2, ZnO, TiO2, Bi2O3 or Al2O3 and an upper partial layer made of a mixed oxide based on zinc and aluminium, especially one having a spinel structure of the ZnAl2O4 type.