Mesoporous carbon "Sibunit" impregnated with aqueous solutions of H2PdCl4 has been studied with STM. The spontaneous reduction of Pd during the impregnation was confirmed by AES. The surface topography depends on the Pd surface coverage. When the Pd content on the surface is small, particles with an average diameter of ca. 2 nm are frequently observed, which are never imaged on the clean carbon support. When the Pd content is high, the surface still consists of small ca. 3-5 nm particles.