An electrostatic spray gun includes a housing for receiving a replaceable fluid container, a nozzle from which fluid is to be sprayed, a device for expelling fluid from the container, and a high voltage generator for applying electrostatic potential to the fluid to form an electrically charged atomized spray at the nozzle. An electrical path from the generator to the nozzle passes through the fluid, entering the fluid prior to its emergence from the nozzle. The container is rigid and fluid is expelled from the container by a piston under pressure exerted thereon through a forward part of the generator.