Wafer processing method

A wafer processing method for bonding a first wafer and a second wafer and processing the first wafer, the wafer processing method comprising:

• producing a provisionally bonded wafer in which a first wafer and a second wafer are provisionally bonded with a relatively weak bonding force;
• forming a ring-shaped modified layer by applying a laser beam to an inner side adjacent to a chamfered portion formed at an outer periphery of the first wafer of the provisionally bonded wafer, and detaching the chamfered portion from the second wafer, with the modified layer serving as a starting point;
• and
• producing a completely bonded wafer with an increased bonding force obtained by annealing the provisionally bonded wafer,
• the wafer processing method further comprising, after the forming the modified layer or after the producing the completely bonded wafer, grinding and thinning the first wafer, with the second wafer being held on a chuck table constituting a grinding apparatus, and removing the chamfered portion of the first wafer that is detached from the second wafer, with the modified layer serving as a starting point.