Intense ion beams are of interest in fusion research for plasma heating, diagnostics, and target compression and in industry for implantation, microfabrication, etc. We report the generation of intense beams of metal ions of Li, Cs, Sn, Ga, and Hg by field-ion emission of molten metal films on solid wire needles. The source is extremely simple and is based on electrohydrodynamic instabilities induced in liquid films under electric stress. In practice, for a point-source or needle emitter, a tungsten needle protrudes from the surface of the molten metal which, with good wetting, flows as a thin film to the needle apex. Application of a potential difference between the needle anode and an apertured cathode results in an electrohydrodynamic instability in the film which is manifested as a filamentary cusp at the needle apex. The electric field intensity at the cusp is sufficient to produce intense atomic-ion emission by field ionization. When the protruding length of the needle through the molten metal pool is appropriately adjusted, the tip becomes self-feeding and continuous ion emission occurs. Direct currents of 50–700 μA can be readily produced from single needles at modest voltages (3–10 kV). Examination of the liquid cusp in an electron microscope shows that the radius of the emitting zone is ?104 Å, suggesting ion current densities in excess of 104 A/cm2. Source scaling can be achieved with an array of needles. Alternatively, one can use a linear or annular edge over which the molten metal flows as a thin film. In the latter source the ion emitting sites are generated along the edge by the field at a frequency given by λ=8πS/3ε0E2, where S is surface tension and E is field strength. Ion emission is accompanied by light emission from a microscopic spot (10–50 μm) at the anode apex. The anode emission process bears some phenomenological similarities to anode spots and cathode spots in vacuum arcs and to pulsed high-current pinched plasma jets formed on pointed anodes or from exploding wires. Such plasmas are known to be dynamic linear pinches. What we have produced is a microscopic metal-vapor plasma ball, and we have found a way of anchoring this to allow continuous operation. We do not know by what mechanism the intense plasma spot forms; almost certainly it is initiated by field ionization, the electrons perhaps being generated by ion collisions with the metal vapor. Heating and evaporation of the anode jet could be by I2R heating or by electrons accelerated across the anode drop between plasma ball and liquid surface. As a stable plasma ball it is novel and readily lends itself to plasma diagnostics. Also by rapidly discharging a high current at high voltage through the anode it should provide a source of a minute dense plasma more reproducibly than presently attained and an intense pulsed source of ions, light, and x rays.