X-ray thin film inspection device

This x-ray thin film inspection device is provided with: an x-ray irradiation unit (40) that is mounted on a first turning arm (32); an x-ray detector (50) that is mounted on a second turning arm (33); and an x-ray fluorescence detector (60) that detects x-ray fluorescence that is generated from an inspection target due to x-ray irradiation. The x-ray irradiation unit (40) includes: an x-ray optical element (43) that is constituted by a confocal mirror, that receives x-rays that are radiated from an x-ray tube (42), that reflects a plurality of convergent x-rays that have been monochromatized at a specific wavelength, and that makes the plurality of convergent x-rays converge on a preset focal point; and a slit mechanism (46) that, from among the plurality of convergent x-rays that have been reflected from the x-ray optical element (43), transmits an arbitrary number of convergent x-rays.