Since the publication of the first practical electron-beam welding equipment by Steigerwald in 1958, electron-beam welding has spread rapidly in all branches of engineering where welding can be applied. To cover the various requirements, countless welder types have been designed, differing in construction, working space volume, workpiece manipulators and beam power. Electron-beam generators (electron guns) designed for welding applications can supply beams with power ranging from a few watts up to about one hundred kilowatts. "Micro-welds" of tiny components can be realized, as well as deep welds up to 300 mm (or even more if needed). Vacuum working chambers of various design may have a volume of only a few liters, but vacuum chambers with the volume of several hundreds cubic meters have also been built.