thin film can be produced with a good reproducibility into a thin film whose c axis is oriented perpendicularly to the substrate surface this production may be by a sputtering process a cvd process or an ion plating process moreover a thin film having a high resistivity can be produced now as one example of the piezoelectric composite thin film resonator having the structure shown in fig7 a description will be made in the case where zno is employed for the piezoelectric thin films 51 and 52 and sio 2 is employed for the thin film 53 film 53 has an algebraic sign of a temperature coefficient of a resonant frequency of zno which is different than the algebraic sign for the thin films 73 and 74 the thickness of the zno films 51 and 52 are each represented by t p4 and the thickness of the sio 2 film 53 is represented by 2t s4 the thickness of the sio 2 films 73 and 74 are each represented by t s5 fig8 shows a relationship between the film thickness ratio t s4 t p4 versus the thickness ratio t s5 t p4 for satisfying the conditions which produce a zero resonant frequency temperature coefficient of a fundamental thickness extensional vibration mode of this resonator the curve of fig8 was theoretically calculated from a distributed parameter equivalent circuit a.