In order to provide a surface acoustic wave device provided with a
pseudo-single crystal aluminum electrode film, having excellent power
durability, easy to manufacture, and possible to grow with good
reproducibility, a titanium buffer film 4 and an electrode film composed
of an aluminum film or an aluminum alloy film are formed on a
piezoelectric substrate 2 composed of lithium tantalate or lithium
niobate. The electrode film 5 comprises a pseudo-single crystal film
composed of two (111) domains. Each of the <111> directions of two
(111) domains tilts in the range of 0 to 10 degrees to the substrate
surface, and the <11-2> directions in the respective (111) domain
planes are 1 to 15 degrees apart.