μ-XRF is the microscopic equivalent of the well-established multielement analytical technique. In this paper, after comparing the interaction of X-ray photons, electrons and protons with matter and an introduction to synchrotron rings and microfocussing of X-rays, the instrumentation for μ-XRF is discussed, both for laboratory source and synchrotron based setups and the analytical characteristics of μ-XRF are contrasted to that of other microanalytical techniques. Also, this issue of quantification of μ-XRF data is addressed; the applicability of the method in archeological and geological analysis is illustrated.