A crystal resonator element include a pair of resonating arms extending from a base, the resonating arms includes a groove, a slope portion is formed in a connection portion of the resonating arms to the base so that a distance between the groove and the outer edge of each of the resonating arms increases as it approaches the base from the resonating arms, and a non-electrode region which extends over a range of areas from a connection portion connected to a first side surface formed along the longitudinal direction of the groove and a connection portion connected to a second side surface facing the first side surface with a bottom portion disposed there between and in which excitation electrodes are not formed is provided in the groove in at least a part of the bottom portion positioned in the slope portion.