The direct STM observation of Ag adatom hopping on the Si(1 1 1)-(7 × 7) surface at temperatures from 25 to 65 °C and for time periods up to 4 h is presented. Individual jumps of Ag adatoms between half unit cells of the surface reconstruction were observed. Different activation energies and frequency prefactors for hops out of two different types of half unit cells were determined. Having considered detailed balance, we obtained the difference in activation energies and the ratio of prefactors. We also observed Ag dimer formation and decay. The influence of the surface structural defect on Ag adatoms behavior and their STM imaging were studied as well.