A quartz crystal resonator element includes a first electrode pad and a second electrode pad disposed on a lower surface of a support arm, and cut sections disposed in both principal surfaces (upper and lower surfaces) of the support arm between the first and second electrode pads so as to overlap each other, and the cut sections extend so that the support arm is cut from the side surface in the +X-axis direction of the support arm to the −X-axis direction, and are provided with first surfaces roughly perpendicular to the X axis and first and second tilted surfaces extending in the +X-axis direction.