Patent ID: 8790997

Claim:
A laser processing method of irradiating a sheet-like object to be processed with laser light while locating a converging point within the object, so as to form first, second, and third modified regions to become a cutting start point in the object along a line to cut, the object having a first main face area and a second main face area on an opposite side of the first main face area, the method comprising: a modified region forming step of forming along the line the first modified region located at the first main face area of the object, the second modified region located at the second main face area of the object, and the third modified region located between the first and second modified regions, the first to third modified regions aligning in a thickness direction of the object; the modified region forming step including the steps of, forming the first modified region discontinuously along the line such that the first modified region includes portions with a modified region formed and portions without a modified region formed; forming the second modified region discontinuously along the line such that the second modified region includes portions with a modified region formed and portions without a modified region formed; and forming the third modified region continuously along the line such that the third modified region includes portions with a modified region formed.