Silicon has been grown on the (8 x 8)-reconstructed beta-Si3N4(0001) surface at 350 degrees C temperature. The pure Volmer-Weber growth mode has induced the formation of nano-sized silicon clusters randomly distributed on the surface. Synchrotron radiation photoelectron spectroscopy and scanning tunneling microscopy have been employed to study the system. A fit to the photoemission spectra, complemented by topographic information, has allowed us to assign each Si2p and Nis component to the different non equivalent sites of silicon and nitrogen atoms.