Patent ID: 7012355

Claim:
A crystal unit comprising: a crystal blank having a hole defined in at least one principal surface thereof, said crystal blank having (i) a region of a reduced thickness including said hole, said region serving as a vibrating region, and (ii) a holding region surrounding the vibrating region, said holding region having a thickness greater than that of the vibrating region; excitation electrodes disposed respectively on opposite principal surfaces of said crystal blank in said vibrating region; extension electrodes extending respectively from said excitation electrodes to respective opposite ends of one side of said crystal blank; and a casing having a step formed therein; wherein said opposite ends of the one side of the crystal blank are fixed to said step by a joining member, and said crystal blank has a notched portion disposed exclusively in the holding region between said one side and said vibrating region and separated from the vibrating region, said notched portion extending from at least one transverse edge of said crystal blank in a transverse direction of said crystal blank.