Abstract: A particle beam, in particular in ionic on the reproduction system, preferably for lithographic purposes, has a particle source, in particular an ion source for reproducing on a wafer a structure designed in a masking foil as one or several transparent spots, in particular openings, through at least two electrostatic lenses arranged upstream of the wafer. One of the lenses is a grating lens constituted by one or two tubular electrodes and by a perforated plate arranged in the path of the beam perpendicularly to the optical axis. The plate is formed by a masking foil which forms the central or first electrode of the granting lens, in the direction of propagation of the beam.