A resonator with stabilized resonant frequency that includes a lower electrode, a plurality of upper electrodes, and a piezoelectric film disposed between the lower electrode and the plurality of upper electrodes. Moreover, an upper lid having a first and second opposing surfaces is provided so that the first surface faces and seals a first surface of the resonator. In addition, a lower lid having a first and second opposing surfaces is provided so that the first surface faces and seals a second surface of the resonator. The resonator further includes a power terminal electrically connected to the upper electrodes and a ground terminal provided on the second surface of the upper lid. The lower electrode is electrically connected to the ground terminal by the upper lid.