The invention relates to a crystal circle and polishing device and method, a piezoelectric vibrator and manufacturing method and device thereof, especially a polishing device and a polishing method for a polishing crystal circle avoiding the crystal circle of the cutting or the damage of cracks formed by the polishing step, providing a crystal circle approximately forming the plate shape of rectangular with angle used for the material of the piezoelectric vibrator. The chamfer angle with curvature is provided forming the curved surface of the angle portion (D1, D2, D3, D4); the angle portion of the angle portion (D1, D2, D3, D4) at least comprises a first curved surface portion and a second curved surface portion, which are made by the different or the same curvature. The benchmark surface of the crystal of the material is confirmed by the first curved surface and the second curved surface.