Particle beam system comprising a particle source; a first multi-aperture plate with a multiplicity of openings downstream of which particle beams are formed; a second multi-aperture plate with a multiplicity of openings which are penetrated by the particle beams; an aperture plate with an opening which is penetrated by all the particles which also penetrate the openings in the first and the second multi-aperture plate; a third multi-aperture plate with a multiplicity of openings which are penetrated by the particle beams, and with a multiplicity of field generators which respectively provide a dipole field or quadrupole field for a beam; and a controller for feeding electric potentials to the multi-aperture plates and the aperture plate so that the second openings in the second multi-aperture plate respectively act as a lens on the particle beams 3 and feed adjustable excitations to the field generators.