Processing method of workpiece

A processing method of a workpiece with a circular disc shape, the workpiece being a semiconductor wafer, the processing method comprising:

• a tape sticking step of sticking a tape to one surface of the workpiece and integrating the workpiece and a frame through the tape;
• a holding step of holding the workpiece by a holding unit with interposition of the tape after the tape sticking step;
• and
• a laser beam irradiation step of irradiating the other surface of the workpiece located on an opposite side to the one surface with a pulsed laser beam having such a wavelength as to be absorbed by the workpiece from a side of the other surface after the holding step, wherein,
• in the laser beam irradiation step, the semiconductor wafer is ablation processed wherein the other surface is annularly irradiated with the laser beam in a state in which orientation of the laser beam is adjusted in such a manner that the laser beam has an angle of incidence formed due to inclination with respect to a normal to the other surface of the workpiece by a predetermined angle.