Acoustic wave device

An acoustic wave device comprising:

• a first piezoelectric substrate including a first main surface and a second main surface that face each other;
• a first function electrode on the first main surface of the first piezoelectric substrate;
• a first signal electrode, a second signal electrode, and a first ground electrode on the first main surface of the first piezoelectric substrate;
• at least one insulation layer on the second main surface of the first piezoelectric substrate;
• a first signal terminal and a second signal terminal provided indirectly on the second main surface of the first piezoelectric substrate with the insulation layer interposed therebetween;
• and
• a ground terminal on the second main surface of the first piezoelectric substrate;
• wherein
• a first acoustic wave filter including the first function electrode, the first signal electrode, the second signal electrode, and the first ground electrode is provided on the first piezoelectric substrate;
• the first signal electrode and the first signal terminal are electrically coupled, the second signal electrode and the second signal terminal are electrically coupled, and the first ground electrode and the ground terminal are electrically coupled;
• and
• the ground terminal includes a contact portion in contact with the second main surface of the first piezoelectric substrate.