Abstract: An X-ray spectrometer having a curved crystal monochromator which diffracts a continuous X-ray beam from an X-ray source to produce a monochromatic X-ray beam. An angle of incidence of the continuous X-ray beam can be changed with respect to the monochromator so as to change the wavelength of the monochromatic X-ray beam which is focused on and taken out from a receiving slit. The X-ray source, the monochromator and the receiving slit must be positioned always on a Rowland circle. The X-ray source and the monochromator can be moved so that the angle of incidence changes, while the receiving slit remains always stationary and the direction of an X-ray path from the center of the monochromator to the receiving slit remains always constant. Such an X-ray spectrometer is usable as an X-ray irradiation system of XAFS (X-ray Absorption Fine Structure) apparatus so that XAFS measurements require no movement of the sample.