To provide a wafer processing method capable of forming an internal modified layer at a proper position without being affected by an insulating film even if the insulating film is formed on a rear surface side of the wafer, and a laser processing device.

A laser processing device 1 comprises: a chuck table 2 which holds a wafer W; laser beam irradiation means 3 which irradiates the wafer W with a laser beam L; and remote-type atmospheric pressure plasma irradiation means 4 which irradiates the wafer W with discharge plasma P. A condensing part 11 of the laser beam irradiation means 3 and an exhaust nozzle 26 of the remote-type atmospheric pressure plasma irradiation means 4 are adjacent to each other. A wafer processing method comprises the steps of: removing an insulating film I by irradiating the wafer with the discharge plasma P from the remote-type atmospheric pressure plasma irradiation means 4 (plasma irradiation step); forming a modified layer K inside the wafer W (modified layer forming step); and dividing the wafer W into devices (division step).