Crystal vibrator, method for manufacturing the same, and crystal vibration device

A crystal vibrator comprising:

• a crystal substrate having:
• a front surface and a rear surface,
• a vibration portion in a region including a center of the crystal substrate, the vibration portion having a first periphery and a first peripheral edge portion having a curved surface shape,
• a first peripheral portion surrounding the first periphery of the vibration portion and having a smaller thickness than the vibration portion and a second peripheral edge portion having the curved surface shape, and
• a first step between the vibration portion and the first peripheral portion in at least one of the front surface and the rear surface of the crystal substrate;
• a first drive electrode on the front surface of the vibration portion of the crystal substrate;
• and
• a second drive electrode on the rear surface of the vibration portion of the crystal substrate.