Composite Sn + C electrodes were sputtered using an electric arc method. As a result, materials representing spherical tin nanoparticles packed in a carbon matrix were synthesized. The carbon matrix reliably separates the nanoparticles, preventing them from contacting and coagulating, which preserves their size. The structure of the material was studied in detail by transmission electron microscopy. The sizes of tin nanoparticles were described by a log-normal distribution, and the average size depended on the pressure of the buffer gas. The carbon structure was studied by Raman spectroscopy. It is established that tin and carbon structures are related to each other, and the processes of condensation of tin vapor and agglomeration of the carbon structure affect each other.