Laser processing device and laser processing method making the resin layer on the inner side difficult to process during processing of a layer on the surface side when a multi-layer resin substrate is subjected to full-cutting processing by a laser processing device

The subject of the present invention is that when a multi-layer resin substrate is subjected to full-cutting processing by means of a laser processing device, the resin layer on the inner side is difficult to process during processing of a layer on the surface side. The laser processing device 1 is a device used for cutting a multi-layer resin substrate P with a first resin layer L1 and a second resin layer L2 from the surface side, and is provided with a first laser oscillator 9A and a second laser oscillator 9B. The first laser oscillator 9A is a device for generating a first laser light R1 for cutting off the first resin layer L1. The first laser light R1, compared with respect to the first resin layer L1, has a lower absorption rate with respect to the second resin layer L2. The second laser oscillator 9B is a device for generating a second laser light R2 for cutting off the second resin layer L2. The second laser light R2, compared with respect to the first resin layer L1, has a higher absorption rate wi