Acoustic wave device

An acoustic wave device, comprising:

• a first resonator including:
• a piezoelectric substrate including a piezoelectric layer including a first main surface and a second main surface opposed to each other;
• a first functional electrode on one of the first main surface and the second main surface;
• and
• a first dielectric film on the one of the first main surface and the second main surface on which the first functional electrode is provided;
• a second resonator sharing the piezoelectric layer with the first resonator, and including:
• a second functional electrode on one of the first main surface and the second main surface;
• a second dielectric film on the first main surface;
• and
• a third dielectric film on the second main surface;
• wherein
• the piezoelectric layer includes a first resonator portion in which the first resonator is provided and a second resonator portion in which the second resonator is provided;
• and
• when a thickness of the first resonator portion is represented by tp1, a thickness of the second resonator portion is represented by tp2, a thickness of the first dielectric film is represented by ts1, a thickness of the second dielectric film is represented by ts2, and a thickness of the third dielectric film is represented by ts3, ts1/tp1<(ts2+ts3)/tp2 is satisfied.