To provide an X-ray fluorescence analytical device enabling fluctuation of a focal position of an irradiation X-ray (primary X-ray) to agree with fluctuation of the surface position of an irradiation object, in order to monitor the metal element concentration in various liquids, the composition or thickness of a membrane or the like by an inline process.

This X-ray fluorescence analytical device is equipped with an X-ray generation source for emitting the primary X-ray, a plurality of spectroscopic elements arranged annularly so that the inner surface constitutes a circle around the optical axis center of the primary X-ray, for monochromatizing the primary X-ray and condensing it onto the irradiation object surface, a spectroscopic element position adjusting means for adjusting positions of the plurality of spectroscopic elements, a secondary X-ray detector for detecting the secondary X-ray emitted from the irradiation object surface by irradiation of the monochromatized primary X-ray, a secondary X-ray detector position adjusting means for adjusting the position of the secondary X-ray detector, an irradiation object surface position detection means for detecting the irradiation object surface position, and a control means for adjusting the positions of the plurality of spectroscopic elements by the spectroscopic element position adjusting means so that the monochromatized primary X-ray is condensed onto the irradiation object surface based on information of the irradiation object surface position detected by the irradiation object surface position detection means.