The invention relates to a plaster, in particular a transdermal, preferably therapeutic system comprising: a cover film； a layer (matrix layer), consisting of a matrix or containing a matrix which can comprise an active ingredient； and a one-piece peeling film. (i) The matrix of the matrix layer is self-adhesive and can be provided with a self-adhesive layer of adhesive between the matrix layer and the peeling film and in addition, a peeling aid can be provided between the matrix layer and the peeling film (if there is no layer of adhesive), or between the layer of adhesive and the peeling film； or (ii) the matrix of the matrix layer is not self-adhesive and is provided with a self-adhesive layer of adhesive between the matrix layer and the peeling film, a peeling aid also being provided between the layer of adhesive and the peeling film.
