A photoelectron spectrometer composed of a cylindrical mirror type of electron energy analyzer and an Al K&agr; x‐ray source is described. Performance tests with a tungsten filament and with gold samples have proved that the analyzer performs well. The doublet peaks of N6and N7of gold were completely resolved, and half‐widths of the two peaks were both found to be about 1.5 eV, which is comparable with the value of 1.3–1.4 eV given by Siegbahnet al.with Mg K&agr; x rays.