A laser processing method for preventing particles from occurring from cut sections of chips obtained by cutting a silicon wafer is provided. An irradiation condition of laser light L for forming modified regions 7.sub.7 to 7.sub.12 is made different from an irradiation condition of laser light L for forming the modified regions 7.sub.13 to 7.sub.19 such as to correct the spherical aberration of laser light L in areas where the depth from the front face 3 of a silicon wafer 11 is 335 .mu.m to 525 .mu.m. Therefore, even when the silicon wafer 11 and a functional device layer 16 are cut into semiconductor chips from modified regions 7.sub.1 to 7.sub.19 acting as a cutting start point, twist hackles do not appear remarkably in the areas where the depth is 335 .mu.m to 525 .mu.m, whereby particles are hard to occur.