Laser processing method

A laser processing method by which an object to be processed can be cut with a high precision is provided. The laser processing method of the present invention irradiates a planar object to be processed 1 with laser light L while locating a light-converging point P within the object 1. Initially, a first modified region 71 to become a start point for cutting is formed along a first line to cut 5a in the object 1. Subsequently, along a second line to cut 5b intersecting the line to cut 5a, a second modified region 72 to become a start point for cutting is formed so as to intersect at least a part of the modified region 71. Then, a fourth modified region 73 to become a start point for cutting is formed along the line to cut 5b. Thereafter, between the modified region 71 and an entrance face 1a of the object 1 where the laser light L is incident, a third modified region 74 to become a start point for cutting is formed along the line to cut 5a so as to intersect at least a part of the modified region 73.