An x-ray monochromator system for the Al Kα emission line has been developed specifically for x-ray photoelectron spectroscopy. It is composed of a fine focus, high power x-ray tube with a water-cooled rotating anode and a spherically bent quartz crystal. The parameters have been chosen to achieve very high resolution with acceptable intensity and to fulfill the geometrical conditions imposed by the electron spectrometer. A description is given of the adjustments and tests of the different components of this equipment. It is demonstrated, on the basis of spectra particularly suitable for this purpose, that a total instrumental line width of 0.3 eV or better is achieved.