An electrostatic velocity analyzer of the Mo¨llenstedt type is described in detail, featuring in particular a high efficiency (through‐put) and a resolution adjustable from about 0.2 to 30 eV (or more) full width at half‐maximum (FWHM). The construction is kept simple by using several commercially available parts. A sweep generator together with a multichannel scaler is utilized to record spectra over an energy range from 0 to 16 000 eV. An experimental calibration technique is described and two energy‐loss spectra obtained by electron impact are given to demonstrate the performance of the analyzer.