The applications of X-rays and the principles of X-ray fluorescence analysis have been described. The following X-ray techniques are presented: EDXRF, WDXRF, TXRF, SXRF, PIXE, SEM-EDS and WDS, EMPA. Several topics are discussed in detail: sources of excitation including excitation with charged particles, detection of characteristic radiation, measurement geometry, spectrometer configurations including also portable instruments, examination of microregions. The statistical evaluation of the measurement results is comprehensively treated. A particular attention is given to the application of XRF in examination of the art objects and the archaeological findings. The main advantages o f XRF are a non-destructive measurement, possibility to measure a very small area and a portability of some instruments. Some limitations of this method are also mentioned. The examples of the historical glass examination from the own research as well as from the literature are presented.