This supplement of Mikrochimica Acta contains selected papers from the Fifth Workshop of the European Microbeam Analysis Society (EMAS) on "Modern Developments and Applications in Microbeam Analysis" which th th took place from the 11 to 15 May 1997 in Torquay (UK). EMAS was founded in 1986 by scientists from many European countries in order to stimulate research in microbe am analysis and into its development and application. The society now has over 350 members from more than 20 countries. An important EMAS activity is the organisation of biennial workshops which focus upon the current status and developing trends in microanalytical techniques. For this meeting EMAS chose to invite speakers on the following subjects: Standardless analysis, EPMA techniques for quantitative near-surface analysis and depth profiling, Matrix corrections in Auger electron and X-ray photon spectroscopy, X-ray analysis and imaging using low voltage beams, Scanning probe and near field microscopies, EPMA of frozen biological bulk samples, Environmen tal SEM and X-ray microanalysis of biological materials, Quantitative elemental mapping of X-ray radiographs by factorial correspondence, X-ray spectrum processing and multivariate analysis, Thin film analysis and chemical mapping in the analytical electron microscope, Wavelength dispersive X-ray spectroscopy, High resolution non dispersive X-ray spectroscopy with state-of-the-art silicon detectors and Recent developments in instrumentation for X-ray analysis. These invited lectures were given by eminent scientists from Europe, the USA, and Australia In addition to the introductory lectures there were poster sessions at which some 110 posters were on display.