An air‐insulated direct‐current electrostatic generator of the Van de Graaff type, characterized by simplicity and low cost and suitable for a wide variety of research applications, is described. The generator, which employs re‐entrant terminals, is capable of 500 kv and produces a short‐circuit current of about 200 microamperes with a single 10″ belt. The manner in which the unit can be extended to higher voltages and currents is indicated, as well as the effect of operation in the presence of CCl4and CCl2F2vapors. The operating principles, design considerations, theory of multiple belts, effect of humidity, problem of surge elimination, and cost are discussed.