Since the beginning nineties, entitled with the catchword "Fuzzy Logic" reports have been given on numerous, predominantly Japanese applications of fuzzy set theory. This had brought about a change in thinking for scientists and practitioners in Europe and, in particular, in Germany. Had the potentials of this new technology for a long time been underestimated, there now suddenly springs up a very high demand for information on this topic. This article gives a survey of the fundamentals of fuzzy set theory and describes potential applications.