The Fourth Symposium on Surface Physics was held to summarize important new developments in theoretical and experimental studies of solid surfaces. In recent years, the physical and chemical properties of surfaces and interfaces have been extensively investigated. This meeting was mainly devoted to the crystallographic and electron structure aspects of surface physics, and to a detailed understanding of the electronic, structural and magnetic properties of clean surfaces, and adsorbed aggregates on surfaces and interfaces. New and newly-refined techniques were presented and discussed. This proceedings volume comprises three main parts: the first contains the invited lectures indicating the main topics of the meeting; the second and third parts summarize the oral papers and posters in a more condensed form.