PURPOSE: To improve resonance frequency temperture characteristic by selecting the Z' axis obtained by turning a crystal by an angle of α (2°∼6°) around the X axis as the thickness direction and selecting the X' axis obtained by turning the crystal by an angle of θ (6°∼10°) around the Z' axis as the broadwise direction and using the cut crystal chip.

CONSTITUTION: A crystal chip (a) is a crystal chip while being turned by an angle α with respect to the X axis by, e.g., α=2°∼6°, and a crystal chip (b) is a crystal chip cut out by turning the crystal around the Z' axis by an angle θ, e.g., θ=6°∼10°. Then a crystal chip C forming a tuning fork is cut out while the lengthwise direction is taken as the Y" axis, the broadwise direction is taken as the X' axis, the thickness direction is takes as the Z' axis on the plane comprising the X' axis and the Y" axis. An exciting voltage is fed to each electrode provided to vibration arms 12, 13 of the crystal chip 1 through the leads 15, 16. The vibration of the vibration arms 12, 13 is vibrated at a prescribed frequency region by making the torsional vibrating frequency of the part (m) coincident with the bending vibration frequency of the part (n).