PURPOSE: To obtain a lithium niobate resonator having excellent reliability by cutting the Z plate of said resonator at the angle rotating 75W105° around the X-axis as the axis of rotation.

CONSTITUTION: The flexuous mode lithium niobate resonator 1 is of the type fixed at both ends cut at 75W105° cutting angle θ and is supported and fixed by means of an adhesive agent, etc. at both ends 3 of the resonator 1 onto a supporting pedestal 2. The pedestal 2 is made of an insulating material such as ceramics, by which the resonator is made strong to disturbance, particularly impact force unlike a cantilever type.