To achieve adequate restoration project, the moment of choice of the type of intervention is a very delicate phase that necessarily involves a thorough understanding of the asset in all its aspects, as the location, the history, the architecture, the state of preservation, the pathologies causing the degradation, the degradation in itself, the analysis of constituent materials. The set of all that can be investigated on a product (cultural), to obtaining important information for subsequent maintenance, conservation and/or restoration actions, is what is called a diagnostic plan. In this case it was applied directly on a monument of national importance: the Royal Villa in Naples (today the Municipal Villa). The analysis were performed in situ and in the laboratory (SEM-EDS) on samples taken directly at the Villa, which allowed the creation of a series of analytical cards, containing digital data, required for the selection of expense future of intervention.
Keywords: Royal Villa; SEM; analytical digital cards; degradation.