1. Method for patterning a substrate using multiple exposure.2.1. The invention relates to a method for patterning a substrate using exposure processes of an adjustable optical system, a multiple exposure being used for producing a structure image on the substrate.2.2. According to the invention, for at least one of the plurality of exposures, the imaging quality of the optical system is determined by means of a respective measurement step and at least one parameter of the optical system that influences the imaging quality is set depending on this.2.3. Use e.g. for the patterning of semiconductor wafers in microlithography projection exposure apparatuses.