A laser processing device includes: a laser light source emitting laser light; a converging optical system converging the laser light at an object to be processed; a reflective spatial light modulator modulating the laser light such that the laser light is caused to branch into 0th order light and ±nth order light (n is a natural number) including at least first processing light and second processing light, and the first processing light is converged at a first converging point and the second processing light is converged at a second converging point; and a light blocking part blocking light to be converged at an outside with respect to the first processing light and the second processing light of the 0th order light and the ±nth order light to be converged at the object.