Abstract: The invention relates to a laser cutting method for cutting a C—Mn steel workpiece, characterized in that laser beam generation means comprising at least one silica fiber with an ytterbium-doped core is used to generate the laser beam. Preferably, the ytterbium-based fiber has a wavelength between 1.07 and 1.1 ?m, preferably 1.07 ?m, the quality factor of the laser beam is between 0.33 and 8 mm.mrad, and the laser beam has a power of between 0.1 and 25 kW. The assistance gas for the laser beam is chosen from nitrogen, helium, argon, oxygen, CO2 and mixtures thereof, and, optionally, it further contains one or more additional compounds chosen from H2 and CH4.