This supplement of Mikrochimica Acta contains selected papers from the Fourth Workshop of the European Microanalysis Society (EMAS) on "Modern Develop- ments and Applications in Microbeam Analysis" which took place in May 1995 in Saint Malo (France). EMAS was founded in 1986 by members from almost all european countries in order to stimulate research, applications and development of all forms of microbeam methods. One important EMAS activity is the...