Efficient transverse energy confinement, and provision of a surface
acoustic wave filter having preferable characteristics of both insertion
loss and shape factor are obtained. In the surface acoustic wave filter,
electrode fingers of one comb electrode are laid in a state of being
inserted to the electrode fingers of the other comb electrode, and a
thick film thicker than each plurality of electrode fingers is produced
in a partial area of the bus bar, and a tip gap is provided between the
top of each plurality of electrode fingers and the end face of the
opposed bus bar, with a distance therebetween set not greater than
0.2.lamda. (where, .lamda. is one period of the comb electrode).