An etching mask is produced for etching a substrate by a photoresist layer being exposed such that areas which are exposed once are not yet completely exposed and, on the basis of a reflective layer which is located under the photoresist layer, additionally exposed areas are exposed completely. In consequence, a first etching mask which is used for etching a substrate can be renewed by a second etching mask in that a photoresist layer which is applied to the first etching mask or instead of the first etching mask is exposed such that areas which have been exposed once are not yet completely exposed, and areas which have been additionally exposed on the basis of a reflective layer which is located under the photoresist layer and corresponds to the first etching mask are exposed completely.