To provide a surface acoustic wave device which makes cracks of a piezoelectric substrate due to stress applied during bump formation and peeling of an electrode layer from the piezoelectric substrate less likely to occur.

A surface acoustic wave device is mounted on a mounted substrate with bumps 13 interposed therebetween, by a flip chip bonding method. A first electrode layer 11 including IDT electrodes 3 to 5 is formed on a first main surface of a piezoelectric substrate 2, and a second electrode layer 12 is formed so as to electrically connect with the first electrode layer 11. The bumps 13 are joined on the second electrode layer 12. When a portion of the second electrode layer 12 to which the bump 13 is joined is referred to as a joining region, a dielectric layer 8, made of a dielectric material having higher hardness than the bumps 13, is provided between the second electrode layer 12 and the piezoelectric substrate 2 in the joining region.