Elastic wave device, radio-frequency front-end circuit, and communication apparatus

An elastic wave device comprising:

• a supporting substrate;
• an acoustic reflection layer provided on the supporting substrate;
• a piezoelectric layer provided on the acoustic reflection layer;
• and
• an interdigital transducer (IDT) electrode provided on the piezoelectric layer;
• wherein
• a metal film is not provided between the acoustic reflection layer and the piezoelectric layer;
• the acoustic reflection layer includes:
• three or more low-acoustic impedance layers;
• and
• two or more high-acoustic impedance layers;
• and
• at least one of a first relationship in which a film thickness of, among the three or more low-acoustic impedance layers, a first low-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a low-acoustic impedance layer closest to the first low-acoustic impedance layer among the three or more low-acoustic impedance layers and a second relationship in which a film thickness of, among the two or more high-acoustic impedance layers, a first high-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a high-acoustic impedance layer closest to the first high-acoustic impedance layer among the two or more high-acoustic impedance layers, is satisfied.