Book and Paper Conservation Centre of the Archives of the Republic of Slovenia received the congratulatory book with the photograph of Kranj from 1860 to carry out an expert examination in the field of conservation and restoration and natural science. The oldest photograph kept by the Archdiocesan Archives in Ljubljana and also the oldest known photograph of Kranj aroused a great deal of curiosity among researchers as the author could be Janez Puhar (Johann Pucher). After visual examinations of the photograph, literature studies, consultations with the competent archivist and Slovenian experts on old photographs, we decided to use the PIXE method as it allows a relatively simple and non-destructive examination. Below is a description of the work method and analysis results.