Direct diode laser processing device and output monitoring method for same

The present invention is provided with: a laser oscillator (11) that has a plurality of laser diodes that oscillate multi-wavelength laser light; a transmission fiber (12) that transmits the multi-wavelength laser light that is oscillated by the laser oscillator (11); a laser processing machine (13) that concentrates the multi-wavelength laser light that is transmitted by the transmission fiber and processes a workpiece (W); a detection mechanism (7) that samples a portion of the multi-wavelength laser light and that detects the optical intensity of the sampled laser light at each wavelength; a monitoring unit that monitors reduction in the output of the multi-wavelength laser light on the basis of variation in the optical intensity of the multi-wavelength laser light at each wavelength; and a control module that controls the plurality of laser diodes on the basis of monitoring results from the monitoring unit (73). As a result, the present invention suitably monitors reduction in the output of the multi-wave