Abstract: A surface acoustic wave element includes: a diamond layer; an alumina nitride layer provided on the diamond layer; a silicon oxide layer provided on the alumina nitride layer; and a pair of electrodes provided between the alumina nitride layer and the silicon oxide layer, the electrodes applying a voltage to the alumina nitride layer. If a thickness of the alumina nitride layer is represented by H1, a thickness of the silicon oxide layer is represented by H2, a wavelength of a surface acoustic wave is represented by ?, x is defined as x=2?H1/?, and y is defined as y=2?H2/?, (x, y) meets all of the following formulas 1 to 4 below. That is, the formula 1 is y?0.750×x+0.325; the formula 2 is y??0.300×x+1.690; the formula 3 is y??0.500×x+0.950; and the formula 4 is y?0.700×x?0.610.

Abstract: A surface acoustic wave element includes: a diamond layer; an alumina nitride layer provided on the diamond layer; a silicon oxide layer provided on the alumina nitride layer; and a pair of electrodes provided between the alumina nitride layer and the silicon oxide layer, the electrodes applying a voltage to the alumina nitride layer. If a thickness of the alumina nitride layer is represented by H1, a thickness of the silicon oxide layer is represented by H2, a wavelength of a surface acoustic wave is represented by ?, x is defined as x=2?H1/?, and y is defined as y=2?H2/?, (x, y) meets all of the following formulas 1 to 4 below. That is, the formula 1 is y?0.750×x+0.325; the formula 2 is y??0.300×x+1.690; the formula 3 is y??0.500×x+0.950; and the formula 4 is y?0.700×x?0.610.