methods are provided for manufacturing piezoelectric vibrating devices that do not contain any unwanted gas or water vapor inside the devices . in an exemplary method , a base wafer is prepared including multiple package bases each having a first main surface and a second main surface . the base wafer also includes a pair of through - holes disposed between adjacent package bases of the base wafer . a piezoelectric vibrating piece is placed on each package base . a lid wafer is prepared that includes multiple package lids . a sealing material is applied to the base wafer or lid wafer in peripheral bands used for bonding the bases and lids together and defines respective interior cavities . the band of sealing material includes a communicating groove that communicates from the inner cavity to the first through - hole . the base wafer and lid wafer are subject to heat and compression to effect bonding . meanwhile , the cavities are allowed to ventilate through the communicating grooves and through - holes to ensure that the cavities have a desired vacuum level or inert gas contents before completion of sealing .