In material machining with electron beams, the energy of a powerfully accelerated and focused electron beam is converted into heat in the focal spot when it strikes the workpiece surface. The penetration depth of the electrons into the workpiece layer is a function of acceleration voltage and the density of the material to be machined. The thermal energy is used to modify material surface properties. Very high-power densities are possible, which can be used for different technologies. The special technological features of electron beam machining are discussed using examples of hardening, melting, welding and drilling. The treatment of tool surfaces (injection molding, forming) with electron beams is used to show how the process can be controlled by a suitable combination of machining frequency and energy density to automatically produce optically brilliant workpiece surfaces.