[Problem]
The present invention aims to solve the problems that size of X-ray monochromater crystal assembly is restricted and the vacuum of the X-ray source and the vacuum of the analysis chamber cannot be separated.
[Solution]
A hard X-ray photoelectron spectroscopy apparatus comprises an X-ray source, an analyzer, a sample manipulator, an analysis chamber, and vacuum evacuation systems, wherein, in a three-dimensional space defined by a XYZ rectangular coordinate axis system, a plate-like sample is arranged to be rotatable around the Z-axis by said sample manipulator (2), wherein said X-ray source comprises an electron gun (3b) which accelerates and focuses electrons, a target which is irradiated with the electrons accelerated and focused by the electron gun to generate an X-ray, monochromater crystal assembly, wherein the monochromater crystal assembly meets the Bragg condition of X-ray diffraction in X-Y plane to diffract/reflect and monochromatize the X-ray generated in said target and extract characteristic X-rays only, and on the other hand, the electron-beam-irradiation position on the target-center of the monochromater crystal assembly-center of the sample is arranged on the Rowland circle to minimize focusing aberration to the sample, the monochromater crystal assembly is located on a circle having a radius twice as large as that of the Rowland circle in a X-Y plane, preferably electron-beam-irradiation position on said target and the center of the sample are located on each of two focuses of an ellipse coming in contact with said Rowland circle in the center of the monochromater crystal assembly, said monochromater crystal assembly has a toroidal surface in Z axial direction acquired by rotating said ellipse coming in contact with said Rowland circle around a straight line connecting the electron-beam-irradiation position on said target and the center of the sample, and, a vacuum vessel for installing these components, wherein the monochromater crystal assembly used for monochromatization with diffraction and reflection of said X-ray source is located on the Rowland circle together with said target and said sample to meet the condition that the dispersed X-ray beam concentrates on the surface of the sample with the minimum aberration, wherein said Rowland circle is located to be orthogonal to the surface of the sample, wherein an optical axis of said analyzer is placed to be perpendicular (in X axial direction) to the incident direction (in Y axial direction) of the X-ray or within a range of ±36 degree angle in a X-Y plane and within a range of ±49 degree angle in a X-Z plane, wherein the sample is such that said X-ray diffracted and reflected by a reflection surface is located on focus positions on the surface of said sample and is obliquely incident on the surface of said sample, so that the spot of said X-ray elongatedly extends along a line in substantially parallel to Y axis (substantially perpendicular to X axis), and wherein an aperture of a slit provided at the entrance of said analyzer is arranged in parallel to a direction where said X-ray spot on the sample surface elongatedly extends.