A piezoelectric bulk wave device that includes a piezoelectric thin plate that is made of LiTaO3, and first and second electrodes that are provided in contact with the piezoelectric thin plate. The piezoelectric bulk wave device utilizes the thickness shear mode of the piezoelectric thin plate made of LiTaO3. The first and second electrodes are each formed by a conductor having a specific acoustic impedance higher than the specific acoustic impedance of a transversal wave that propagates in LiTaO3. When the sum of the film thicknesses of the first and second electrodes is defined as an electrode thickness, and the thickness of the piezoelectric thin plate made of LiTaO3 is defined as an LT thickness, the electrode thickness/(electrode thickness+LT thickness) is not less than 5% and not more than 40%.