An ion source generating ions by matrix-assisted laser
desorption/ionization (MALDI) comprising a MALDI sample support and a
solid-state the laser system generating a pulsed laser beam, which has a
wavelength in the range between 332 and 342 nanometers and is spatially
shaped in the solid-state laser system such that the spatial intensity
distribution of the laser beam on the MALDI sample support exhibits more
than one intensity peak.