A method applies layers to channels of a resistance heating element, where the channels are arranged in a honeycomb structure and receive a medium to be heated. Adjacent layers communicate with electrically conducting end-face metallizations of the resistance heating element and have, at an opposite end, an insulation region in relation to another respective end-face metallization. To apply the layers, a miniature lance is immersed into the channel to be coated. The miniature lance is hollow, closed at a lower end, has an upper end communicating with a reservoir of metal paste, and includes outlets in a lower region that are directed to inner walls. Metal paste is uniformly applied to the inner walls of the channel by pressure while simultaneously moving the miniature lance. The miniature lance is inserted into an adjacent channel for coating inner walls of the adjacent channel from the other end-face metallization side.