Without increasing the complexity and cost of the manufacturing process, can suppress transverse-mode ripples effectively provides an acoustic wave device.
The IDT electrode 3 is disposed on the piezoelectric substrate 2, the IDT electrode 3, in at least one of the first, second electrode fingers 13 and 14, the width direction dimension as compared to the central longitudinal is largely the wide portions 13a to 13d, 14a through 14d are provided on at least one side of the proximal and distal than the central region, at least one of the first and second bus bars 11 and 12, bus bars having a plurality of openings 15 which are distributed along the length, at least one of the first and second bus bars 11 and 12, the first or second electrode fingers 13 and 14 than the opening 15 located on the side, has an inner bus bar portion 11A extending in the length direction of the first and second bus bars 11 and 12, a central bus bar portion 11B in which the opening 15 is provided, the outer bus bar portion 11C, acoustic wave device 1.