To elucidate the origin of armours supposed to be from Lombardy according to art-historians, the very small Slag Inclusions entrapped in the metallic matrix were analysed on the samples taken on armours. This paper presents the analytical protocol, based on the coupling of LA-ICP-MS and confocal SR-µ-XRF (confocal Micro-X-ray fluorescence under Synchrotron Radiation) developed to obtain trace element information from this kind of inclusion. Confocal SR-µ-XRF has been applied to inclusions of ancient iron artefacts for the first time. The reliability and reproducibility of the procedure developed for the trace elements quantifying have been checked by a comparison of the results obtained by LA-ICP-MS and by confocal SR-µ-XRF. Our first results allow us to draw some preliminary observations on the origin of the samples.