Method of processing bonded wafer which is to process the bonded wafer with a ground wafer on a carrier wafer

A novel technological solution is proposed to prevent the peeling off of a ground wafer or the formation of cracks in a ground wafer due to the unattached area when grinding a bonded wafer. A method of processing a bonded wafer is provided, The aforementioned bonded wafer is a wafer with a ground wafer on a carrier wafer, and the method of processing a bonded wafer includes the following steps: an unattached area detection step for detecting an unattached area between the carrier wafer and the ground wafer in the peripheral edge portion of the bonded wafer; an unattached area removal step for removing an area corresponding to the unattached area in the peripheral edge portion of the bonded wafer detected in the unattached area detection step by cutting the ground wafer with a cutting blade; and a grinding step for grinding the ground wafer of the bonded wafer after performing the unattached area removal step.