A simple two‐crystal spectrometer was constructed using a commercial single‐crystal spectrometer, i.e., the second crystal and the detector were attached on the 2&thgr; arm of a single‐crystal spectrometer. The angle between the second crystal and the detector is preset to an optimum angle for the measurement region of interest. The condition for geometrically ideal analysis can be satisfied by rotating the &thgr; axis and detector arm (2&thgr; arm) at a rotation ratio of 1:3 using an external pair of gears whose ratio is 3:1. The wavelength can be directly read according to Bragg’s diffraction law, like a commercial two‐crystal spectrometer. We measured sulphur‐K&bgr; spectra for several sulphur compounds. We conclude, from several measurements, that the spectra obtained with a high‐resolution can be an important and powerful tool for the study of the valence band and can also be applied to chemical‐state analysis.