A review of papers devoted to study and use of the emission of electrons from a metal in contact with plasma clusters formed on explosion of micropoints on a cathode under the influence of thermionic field emission current of high density. A systematic discussion is given of questions of thermionic field emission of electrons from the metal, energy dissipation in cathode micropoints, explosive evaporation of the points, and formation of localized plasmas–cathode flares, which stimulate a rapid increase in electron emission from the cathode. A discussion is given of questions associated with study of the removal of cathode material in the operation of cathode flares and also with the investigation of the parameters of the plasma and the kinetics of its dispersion. The laws governing the removal of electrons from the cathode flare plasma are discussed, as well as the mechanism of electron emission from the metal to the cathode flare plasma. A separate section is devoted to the use of explosive emission in high-current electron accelerators and pulsed x-ray sources. The role of this phenomenon in initiation of electrical discharges in vacuum and gas is also discussed.