A surface acoustic wave device utilizing a Rayleigh wave includes a LiNbO.sub.3 substrate having Euler angles of (0.degree..+-.5.degree., .theta..+-.5.degree., 0.degree..+-.10.degree.), an electrode which is disposed on the LiNbO.sub.3 substrate and which includes an IDT electrode primarily including Cu, a first silicon oxide film disposed in a region other than the region in which the electrode is disposed, the first silicon oxide film having a film thickness substantially equal to the thickness of the electrode, and a second silicon oxide film arranged to cover the electrode and the first silicon oxide film, wherein the film thickness of the electrode is within the range of about 0.12.lamda. to about 0.18.lamda., where .lamda. represents the wavelength of a surface acoustic wave, and .theta. of the above-described Euler angles of (0.degree..+-.5.degree., .theta..+-.5.degree., 0.degree..+-.10.degree.) is in the range satisfying the following Formula (1): .theta.=32.01-351.92.times.exp(-T.sub.Cu/0.0187) Formula (1) where T.sub.Cu is a value of Cu electrode film thickness normalized with the wavelength .lamda..