The paper presents the experimental results on the processing of planar and cylindrical metal surfaces by means of pulsed electrical discharges (IED). It has been shown that the result of the interaction of the plasma channel on the surface to be treated arise some rough called Taylor cones. The emergence of these cones is possible processing certain energy regimes. Training workpiece surface roughness tapered DEI apply directly leads to increasing its active area. Currently this phenomenon can be used successfully to manufacture cathodes using electron beam installations meeting and the concentration of power and thermal fields in active areas of emission cathodes in the mail. Workpiece surface has a special geometrical-electron emission would facilitate increased from the same raw tracks by this method.