Abstract: An electrostatical powder coating method starts out from a metallic surface provided with an oil film as a protection against corrosion during storing and transportation. Resin powder is applied to the surface without prior removal of the oil film. The powder layer is melted in a furnace and subsequently hardened by cooling. It is preferred that an amount of heat is supplied by the furnace which is sufficient to evaporate the oil. Preferably, an oil is used which is stable during heating as long as it remains on the work piece surface. This includes the possibility that all of the oil or at least some components thereof diffuse and evaporate through the powder layer during heating or, alternatively, that part or all of the oil remains on the work piece during the heat treatment and mixes with the powder layer. In both cases the quality of the resin coating is not deteriorated by the oil film.