An acoustic wave element comprising: a piezoelectric substrate having an upper surface; a first excitation electrode configured to excite and output a first main acoustic wave on the upper surface of the piezoelectric substrate; a first receiving electrode configured to receive the first main acoustic wave; a first propagation path configured to allow the first main acoustic wave) to propagate along the upper surface of the piezoelectric substrate from the first excitation electrode to the first receiving electrode; a second excitation electrode configured to excite and output a second main acoustic wave on the upper surface of the piezoelectric substrate; a second receiving electrode configured to receive the second main acoustic wave; a second propagation path configured to allow the second main acoustic wave to propagate along the upper surface of the piezoelectric substrate from the second excitation electrode to the second receiving electrode; and a sensing portion provided above the first propagation path and the second propagation path, and configured to react to an object substance, wherein the first propagation path is configured such that the first main acoustic wave passes through the sensing portion a plurality of predetermined times along the first propagation path, wherein the second propagation path is configured such that the second main acoustic wave passes through the sensing portion a plurality of predetermined times along the second propagation path, wherein the first receiving electrode is configured to output a first signal in response to the received first main acoustic wave, wherein the second receiving electrode is configured to output a second signal in response to the received second main acoustic wave, and wherein the first excitation electrode, the second excitation electrode, the first receiving electrode, and the second receiving electrode are disposed such that the first signal and the second signal are added so as to strengthen each other. a piezoelectric substrate having an upper surface; a first excitation electrode configured to excite and output a first main acoustic wave on the upper surface of the piezoelectric substrate; a first receiving electrode configured to receive the first main acoustic wave; a first propagation path configured to allow the first main acoustic wave) to propagate along the upper surface of the piezoelectric substrate from the first excitation electrode to the first receiving electrode; a second excitation electrode configured to excite and output a second main acoustic wave on the upper surface of the piezoelectric substrate; a second receiving electrode configured to receive the second main acoustic wave; a second propagation path configured to allow the second main acoustic wave to propagate along the upper surface of the piezoelectric substrate from the second excitation electrode to the second receiving electrode; and a sensing portion provided above the first propagation path and the second propagation path, and configured to react to an object substance, wherein the first propagation path is configured such that the first main acoustic wave passes through the sensing portion a plurality of predetermined times along the first propagation path, wherein the second propagation path is configured such that the second main acoustic wave passes through the sensing portion a plurality of predetermined times along the second propagation path, wherein the first receiving electrode is configured to output a first signal in response to the received first main acoustic wave, wherein the second receiving electrode is configured to output a second signal in response to the received second main acoustic wave, and wherein the first excitation electrode, the second excitation electrode, the first receiving electrode, and the second receiving electrode are disposed such that the first signal and the second signal are added so as to strengthen each other.