Abstract: Electromechanical knocking device and knocking method for working, smoothing and cold-hardening the surface of tools, machine parts and other parts by hammering an impact head onto the surface of the said parts by means of mounting them on a machine tool or a robot. The impact head (1a) is fastened to a support (1b), which has a ferromagnetic part (1c). A magnetic field (B1) keeps the support for the impact head in a defined position of rest. On the support for the impact head (1b) there is at least one coil (4), which is located in the first-mentioned magnetic field (B1) or in a different magnetic field (B2) and through which an alternating current or pulsed current (12) with or without a variable direct current component flows. As a result, the impact head (1a) is made to oscillate with a defined impact frequency, impact amplitude and zero crossing.