The invention relates to a laser-supported material processing device, comprising a laser (14) for providing a pulsed laser beam (16), a measuring arrangement (30, 32, 34, 36, 38) in order to obtain measured values of a fundamental wave power of the laser beam and of a power of at least one higher harmonic generated from the laser beam by means of frequency multiplication, and an evaluating unit (22) connected to the measuring arrangement, which is designed to examine the quality of the laser beam (16) according to the measured fundamental wave power, the measured power of the higher harmonic, and a set radiation power of the laser (14). By calculating the quotient of the measured fundamental wave power and of the measured power of the higher harmonic, the present conversion efficiency of the frequency multiplication can be determined. Said present conversion efficiency of the frequency multiplication is a measure of the quality of the wave front and the pulse duration of the laser beam (16).
