Method of making surface acoustic wave device

A method of producing a surface acoustic wave device having first and second surface acoustic wave elements provided on a piezoelectric substrate, comprising the steps of:

• forming an interdigital transducer of the first surface acoustic wave element on the piezoelectric substrate, the interdigital transducer having input-output terminals electrically connected via a short-circuiting electrode;
• providing a resist on the surface of the substrate where the interdigital transducer of the first surface acoustic wave element and the short-circuiting electrode are formed;
• heating the resist;
• removing the resist only from an area where the second surface acoustic wave element is to be formed;
• applying a conductive film to the piezoelectric substrate, the conductive film having a thickness that is different from a thickness of the interdigital transducer of the first surface acoustic wave element;
• patterning the conductive film to form an interdigital transducer of the second surface acoustic wave element;
• cutting the short-circuiting electrode to electrically disconnect the input-output terminals of the interdigital transducer of the first surface acoustic wave element;
• forming an insulating film on the interdigital transducers of the first and second surface acoustic wave elements;
• and
• decreasing the thickness of the insulating film to adjust frequency characteristics of at least one of the first and second surface acoustic wave elements.