A lift-off method transfers onto a transfer substrate an optical device layer of an optical device wafer in which the optical device layer is formed over a front surface of an epitaxy substrate through a GaN buffer layer. The lift-off method includes: bonding the transfer substrate onto a front surface of the optical device layer through a bonding layer to form a composite substrate; applying a pulsed laser beam of such a wavelength as to be transferred through the epitaxy substrate constituting the composite substrate but to be absorbed in the buffer layer from a back surface side of the epitaxy substrate, to break the buffer layer; and peeling the optical device layer from the epitaxy substrate and transferring the optical device layer onto the transfer substrate, after the buffer layer breaking step is performed.