To prevent a surplus of conductive adhesive material reaching the wall surface from flowing into an incurrent canal and creeping up the wall surface by providing the incurrent canal, which prevents electrical short circuit of the conductive adhesive material and a welding ring to the outside of an outer peripheral edge part of a crystal piece.

A crystal oscillator is constituted by tightly sealing an IC chip 1 and a crystal piece 2 in a container 3 in which a container main body having a welding ring 8 on the upper surface 4 and a metal cover 5 are seam-welded. Then, an incurrent canal 12 is provided on a horizontal surface of a step part which fixes both end parts of the crystal piece 2. That is, the incurrent canal 12, which goes through a second frame body 7b, is provided. The incurrent canal 12 is defined as the canal 12 of a (hook) shape, in a way in which it surrounds the both end parts of the crystal piece 2 between both ends of the crystal piece 2 and a wall surface of the step part. With such a structure, even if surplus portion of conductive adhesive material 11 flows out, the surplus flows in the incurrent canal 12. Therefore, the device prevents electrical short circuit of the conductive adhesive material 11 and the welding ring 8 by preventing the surplus from creeping up the wall surface.