An acoustic wave device includes a silicon oxide film, a lithium tantalate film, an IDT electrode, and a protection film that are laminated on a support substrate made of silicon. A wavelength normalized film thickness of a lithium tantalate film is denoted by TLT, an Euler angle is θLT, a wavelength normalized film thickness of the silicon oxide film is TS, a wavelength normalized film thickness of the IDT electrode in terms of aluminum thickness is TE, a wavelength normalized film thickness of a protection film is TP, a propagation direction in the support substrate is ψSi, and a wavelength normalized film thickness of the support substrate is TSi. Values of TLT, θLT, TS, TE, TP, and ψSi are set such that Ih corresponding to an intensity of a response of a spurious response represented by Formula (1) is greater than about −2.4 in a spurious response.