Acoustic wave device

An acoustic wave device comprising:

• a piezoelectric layer made of lithium niobate or lithium tantalate;
• and
• at least one pair of electrodes opposed to each other in a direction intersecting a thickness direction of the piezoelectric layer;
• wherein
• d/p is about 0.5 or less, where d is a thickness of the piezoelectric layer and p is a distance between centers of electrodes adjacent to each other in the at least one pair of electrodes;
• the at least one pair of electrodes extends in a longitudinal direction;
• the at least one pair of electrodes includes a first electrode and a second electrode having sectional shapes different from each other in any cross section in a direction orthogonal or substantially orthogonal to the longitudinal direction of the at least one pair of electrodes;
• and
• an inclination angle of at least a portion of an electrode side surface of the first electrode relative to the piezoelectric layer is different from an inclination angle of at least a portion of an electrode side surface of the second electrode in any cross section in the direction orthogonal or substantially orthogonal to the longitudinal direction of the at least one pair of electrodes.