A laminating step includes a first bonding step of bonding a circuit layer of a second wafer to a circuit layer of a first wafer, a grinding step of grinding a semiconductor substrate of the second wafer, and a second bonding step of bonding a circuit layer of the third wafer to the semiconductor substrate of the second wafer. In a laser light irradiation step, a modified region is formed and a fracture extends from the modified region along a laminating direction of a laminated body by irradiating the semiconductor substrate of the first wafer with a laser light.