An optical device wafer processing method for transferring an optical device layer of an optical device wafer onto a transfer member includes: a dividing groove forming step of forming dividing grooves in a buffer layer; a transfer member joining step of joining the transfer member to a front surface of the optical device layer; and a laser beam applying step of applying a pulsed laser beam from a back surface side of a crystalline substrate. In the laser beam applying step, the buffer layer, or the buffer layer and part of the optical device layer, left without being divided in the dividing groove forming step, are modified in nature.