We report on a growth of single crystals of Pd clusters on highly oriented pyrolytic graphite (HOPG) and mica. On HOPG, edges of the clusters were parallel to the imaged substrate atom rows. On mica, both clusters with edges parallel to and 30-degrees off from the imaged atom rows were observed. The atomic resolution with a separation of 0.28 nm on Pd clusters on mica was obtained with atomic force microscopy (AFM). We propose structural models for the epitaxial nature of Pd on HOPG and mica.