In a particle multi-beam structuring apparatus for forming a pattern on a target's surface using a beam of electrically charged particles, during exposure steps the particle beam is produced, directed through a pattern definition means producing a patterned particle beam composed of multiple beamlets, and projected by an optical column including a controllable deflection means onto the target surface to form, at a nominal location on the target, a beam image comprising the image of defining structures in the pattern definition means. The beam image's nominal location relative to the target is changed between exposure steps. The actual location of the beam image is varied within each exposure step around the nominal location, through a set of locations realizing a distribution of locations within the image plane around a mean location coinciding with the nominal location, thus introducing an additional blur which is homogenous over the entire beam image.