A surface acoustic wave device includes: interdigital transducers; first
electrode pads that are connected to the interdigital transducers through
wire patterns; and a piezoelectric substrate on which the interdigital
transducers, the first electrode pads, and the wire patterns, are formed.
In this surface acoustic wave device, at least one of the first electrode
pads is not connected to a ground pattern, and the piezoelectric
substrate has a conductivity in the range of 10.sup.-12/.OMEGA.cm to
10.sup.-6/.OMEGA.cm.