Total reflection X-ray fluorescence spectrometry (TXRF) is a trace elemental micro analysis technique based on conventional energy dispersive X-ray fluorescence. It has become increasingly popular in the last few decades and is applied in almost every field of trace elemental analysis where low detection limits and multi element capabilities are required. Like all X-ray techniques TXRF is non-destructive making it highly useful and important in areas where samples are precious and/or need to be available for further characterization. The ability of probing extremely small sample amounts makes TXRF a superior analytical technique for samples of limited amount. New table top instruments make this technique affordable and versatile as it can be used for field research as well as process monitoring in industrial settings without requirements like vacuum or cooling water circuits. In the semi-conductor industry TXRF is routinely applied to scan wafers for impurities on the surface and in near surface layers.9 This article introduces the basic principle of TXRF, its instrumental features, and discusses various applications of this technique. For a more in-depth treatment of the topic the reader is referred to the book of Klockenkämper and von Bohlen and the reviews of Streli and Wobrauschek listed under suggested further reading.