The deterioration of Bronze Age objects from the archaeological site at Fort-Harrouard (France) has been studied, firstly, in relation to their external appearance and the elemental composition of the sound metal. A relationship between the composition of the corroded surface and the underlying sound metal was deduced. In addition, examination of metallographic sections of one of the bronzes allowed the differentiation of corrosion processes which are related to the shape of the object: the stratification of the corrosion products and the intergranular and transgranular corrosion processes. The existence of a pseudomorphic microstructure suggests that the mechanism of deterioration may be stratigraphic, which may be explained by the growth of the corrosion products in fissures which do not involve periodic precipitation.