A method is disclosed for the mask-etching of a piercing element having an elongate shaft, a distally protruding tip, a proximal holding part, and a laterally open collecting channel that collects bodily fluid and extends along the shaft as far as the area of the tip, wherein a side of a double-sided etching mask is applied respectively to the two sides of a substrate and, under the action of an etching agent, the piercing element is formed as a part made by chemical blanking, wherein a channel side of the etching mask is provided with a channel etching slit for unilateral etching of the collecting channel.
