Abstract: The invention concerns a column for producing a focused particle beam comprising: a device (100) focusing particles including an output electrode (130) with an output hole (131) for allowing through a particle beam (A); an optical focusing device (200) for simultaneously focusing an optical beam (F) including an output aperture (230). The invention is characterized in that said output aperture (230) is transparent to the optical beam (F), while said output electrode (130) is formed by a metallic insert (130) maintained in said aperture (230) and bored with a central hole (131) forming said output orifice.