a surface acoustic wave (SAW) chip having:

IDT electrodes disposed on a main surface of a piezoelectric substrate;

extraction electrodes extracted from the IDT electrodes; and

a metal bonding portion disposed along an entire periphery of the main surface of the piezoelectric substrate; and

a cover having:

through-holes in an insulating substrate at positions corresponding to the extraction electrodes of the SAW chip;

a metal bonding portion disposed along an entire periphery of a lower surface of the insulating substrate;

connection electrodes disposed on the lower surface of the insulating substrate along circumferences of openings of the through-holes; and

external electrodes disposed on an upper surface of the insulating substrate in peripheries of openings of the through-holes;

concave portions disposed at positions at least partially overlapping with the external electrodes on the upper surface of the cover;

wherein the SAW chip and the cover are bonded in a body by bonding the metal bonding portion of the SAW chip and the metal bonding portion of the cover and bonding the extraction electrodes of the SAW chip and the connection electrodes of the cover so as to hermetically seal the IDT electrodes within a space defined between the SAW chip and the cover, and

wherein the IDT electrodes and the external electrodes are electrically connected to each other through a conductive material in the through-holes that is independent from the connection electrodes and the external electrodes.