|For the first time 4f-core levels of mass-separated small Lead and Gold-Clusters in their gaseous phase were measured at the FEL FLASH. Anionic Gold-Clusters of N=39-130 atoms showed a binding energy shift by cluster size that conformed with the predictions of the metallic sphere model. Measurements of anionic Lead-Clusters of N<20 atoms resulted in systematic differences between measurements of 5d-core levels. Possible explanations are discussed. Emissions of secondary electrons, which where detected in all experiments, were analysed by means of a Monte-Carlo-Simulation.