A method of manufacturing semiconductor elements includes: disposing a semiconductor layer made of a nitride semiconductor on a first wafer; and bonding a second wafer to the first wafer via the semiconductor layer. The first wafer has an upper surface including a first region and a second region surrounding a periphery of the first region and located lower than the first region. In a top view of the first wafer, a first distance between an edge of the first wafer and the first region of the first wafer in each of a plurality of first directions parallel to respective m-axes of the semiconductor layer is smaller than a second distance between the edge of the first wafer and the first region of the first wafer in each of a plurality of second directions parallel to respective a-axes of the semiconductor layer.