Piezoelectric device and package thereof

A package for a piezoelectric resonator, includes an insulating base that has a rectangular box shape and made of laminated thin ceramics sheets, and a lid that is made of a thin rectangular sheet of transparent glass material and bonded on the top surface of the base. A tuning fork type quartz crystal resonator element is hermetically sealed in the package. The corners of the lid are cut off diagonally at an angle of approximately 45 degrees or rounded so as to correspond to the cutouts of quarter circles at the corners of the base that result from via holes for wiring inside the base. A predetermined sealing width on the top surface of the base between the lid and the inner periphery of the base and a sufficient margin width between the periphery of the lid and the outer periphery of the base are ensured at the corners. The base has a through hole which enables the inside of the package to communicate with the outside and is hermetically sealed in a vacuum atmosphere with sealing medium after the lid is bonded. Sufficient bonding and sealing strength between the base and lid is ensured while miniaturization and flattening of a piezoelectric resonator are implemented. Gas within the package is minimized and the package can be sealed with the inside being subject to a high vacuum.