A wafer processing method divides a wafer into a plurality of individual devices along a plurality of crossing division lines formed on the front side of the wafer. The method includes a functional layer removing step of applying a CO2 laser beam to the wafer along each division line with the spot of the CO2 laser beam, having a width corresponding to the width of each division line set on the upper surface of each division line, thereby removing a functional layer along each division line to form a groove along each division line where the functional layer has been removed, and a groove shaping and debris removing step of applying a laser beam having a wavelength in the ultraviolet region to the wafer along each groove, thereby removing debris sticking to the bottom surface of each groove and also shaping the side walls of each groove.