A projection exposure method for the exposure of a radiation-sensitive substrate arranged in the region of an image surface of a projection objective with at least one image of a pattern of a mask arranged in the region of an object surface of the projection objective includes exposing the substrate with the image of the pattern in an effective image field of the projection objective during an exposure time interval and also altering a relative positioning between a surface of the substrate and a focus surface of the projection objective during the exposure time interval in such a way that image points in the effective image field are exposed with different focus positions of the image of the mask during the exposure time interval. An active compensation of at least one portion of at least one imaging aberration induced by the change in the focus positions during the exposure time interval has the effect that the imaging quality is not significantly impaired by the alteration of the focusing during the exposure time interval.