A surface acoustic wave device is provided. The surface acoustic wave
device includes a piezoelectric substrate and an IDT which is disposed on
the piezoelectric substrate and made of Al or an alloy containing Al as a
main component and using an SH wave as an excitation wave, wherein the
piezoelectric substrate is a rotated Y-cut quartz plate having a cut
angle .theta. set to a range of -64.0.degree.<.theta.<-49.3.degree.
rotated counterclockwise from a Z crystalline axis and a propagation
direction of a surface acoustic wave set to a direction of
90.degree..+-.5.degree. with respect to an X crystalline axis, wherein,
when a wavelength of an excited surface acoustic wave is denoted by
.lamda., an electrode film thickness H/.lamda. normalized with wavelength
of the IDT is set to a range of 0.04