A SAW filter includes a piezoelectric body, an IDT electrode on the piezoelectric body, and signal wiring electrically connected to the IDT electrode. The signal wiring has a thickness not less than a skin depth specified based on the frequency of a signal passing through the signal wiring and the electrical conductivity of the signal wiring. As a result, the signal wiring has low propagation loss of the signal passing through it, so that the SAW filter has excellent transmission characteristics.