To make parallel X rays applied to a sample and to fully secure the X-ray intensity by irradiating the sample with dispersion X rays coming out of a light reception slit after condensation by a curved crystal monochromator after turning the dispersion X rays into parallel beams by a parabolic multilayer mirror.

The wavelength of the X rays 22 coming out of the light reception slit 14 can be changed by changing the relative position relationship among an X ray source 10, the light reception slit 14, and the curved crystal monochromator 12. The X rays 22 are reflected by the parabolic multilayer film mirror 24 to become parallel beams 26. The parallel beams 26 are transmitted through a transmission type X-ray detector 28 and enter the surface of the sample 30 under total reflection conditions. Fluorescent X rays 36 coming out of the sample 30 are detected by a fluorescent X-ray detector 38.