The X-ray analyzer is arranged for conduction both an X-ray fluorescence analysis and X-ray diffraction comprises an X-­ray source (1), an X-ray guide tube (2) for collecting X-­ray emitted from said X-ray source (1), a sample table (4) disposed in the vicinity of an end of said X-ray guide tube (2) for placing a sample to be subjected to the application of the above described X-rays thereon, and an X-ray detect­or (6). Said sample table (4) and said X-ray detector (6) are disposed within the same one vacuum tank (5) and an in­side of said X-ray guide tube (2) is opened into said va­cuum tank (5). Preferably, the X-ray guide tube (2) compri­ses at least in the range of an X-ray beam outlet a para­boloid of revolution shape with an essentially cylinder type of an outlet end tube portion (23). With the X-ray analyzer according to the present invention, the X-ray beams are highly parallel to each other, so that is is easy to set the conditions for the total reflection of the beams incident upon the sample, whereby for example, the so-call­ed total reflection XS-ray fluorescence analysis becomes possible.