A semiconductor element includes a semiconductor layer, an electrode, an adhesion layer, and an insulating layer. The electrode is disposed over the semiconductor layer and has a first upper surface and a second upper surface disposed further away from the semiconductor layer than the first upper surface. The adhesion layer is disposed on the first upper surface of the electrode so that the second upper surface of the electrode is disposed further away from the semiconductor layer than an upper surface of the adhesion layer. The insulating layer covers from the upper surface of the adhesion layer to the semiconductor layer.