Electron microscopy is a technique for obtaining direct information about the structure of matter even at the atomic scale. It is the basic method for studying the fine structure of biological samples. It is a powerful technique in materials science and has applications in many fields of research, such as physics, chemistry, and mineralogy. Information that can be obtained includes: – the size, shape, distribution and sometimes the chemical composition of microstructural entities – the direct, high-resolution observation of lattice defects and strains – the relationship between the properties and microstructure of matter – the dynamic observation of structural changes produced mechanically, thermally, electrically, magnetically, chemically, etc. Electron microscopy is developing very rapidly. This progress concerns instrumentation (development of high-power microscopes up to 10 MV, of scanning electron microscopes with atomic-sized spots), observation and sample preparation techniques (such as weak-beam techniques or stereoscopy), and contrast theory (especially diffraction contrast and phase contrast). It is therefore necessary to update electron microscope users with refresher courses. International conferences have failed to do this because they are too scattered and too specialized. Training courses are especially essential for scientists in developing countries. Because of the many applications of electron microscopy in the various branches of science, it is also necessary to encourage contacts among the three main groups of scientists interested in electron microscopy (electron microscope users, contrast theory experts, and instrument designers), so that each group can learn about existing problems and perspectives in the other fields in order to harmonize the development of electron microscopy. Finally, periodic meetings are needed to stimulate discussion on specialized topics that could foster fundamental advances in the near future.