Abstract: Process and device for cleaning pollutants from a surface using a laser for applying laser pulses to the surface to be cleaned, in which the laser is pulsed in pulse durations not exceeding 30 nanoseconds, the area on the surface is contacted with the pulsating laser, the surface is cleaned in the absence of an observably thermal effect, and the laser is removed from the area on the surface after the area is cleaned, the laser beam is manipulated by means of a hand piece, and an optical system is provided to separate the laser beam into a plurality of individual laser beams with energies approximately equal to each other, and guided by an optical fiber assembly together with a recombining of the individual beams into a single laser beam, and the afocal optical assembly for adjusting the diameter of the recombined laser beams.