An AT-cut crystal resonator plate (2) includes a first main surface (2a) on which a first excitation electrode (211) is formed and a second main surface (2b) on which a second excitation electrode (212) is formed. The AT-cut crystal resonator plate (2) further includes: a substantially rectangular-shaped vibrating part (21) that is piezoelectrically vibrated when a voltage is applied to the first excitation electrode (211) and the second excitation electrode (212); a holding part (22) protruding from a corner part (21a) of the vibrating part (21) in a Z′ axis direction of the AT-cut crystal; and an external frame part (23) configured to surround an external circumference of the vibrating part (21) and to hold the holding part (22).

A crystal element includes a vibration part, a holding part, an electrode part, and a recess that corresponds to a recess and/or protrusion. The vibration part has a pair of vibration-part main surfaces. The holding part is formed integrally with the vibration part to be connected to an outer edge of vibration part and has a pair of holding-part main surfaces and holding-part side surfaces. The electrode part is provided at the vibration-part main surfaces. The recess is located at the holding-part side surfaces.

A quartz crystal resonator that includes a quartz crystal element having main surfaces extending in a plane φ degrees around a Z axis of the quartz crystal element and θ degrees around an X′ axis of the quartz crystal element; and an electrode in contact with the quartz crystal element, where x=t/T≥0.01, |φ−(−98.6x.sup.3+114.0x.sup.2−22.3x+1.3)|≤5 and |θ−(−9.5x.sup.3−10.9x.sup.2+1.4x+35.3)|≤0.5, wherein T is a thickness of the quartz crystal element and t is a thickness of the electrode.

A quartz crystal resonator that includes a quartz crystal element having main surfaces extending in a plane φ degrees around a Z axis of the quartz crystal element and θ degrees around an X′ axis of the quartz crystal element; and an electrode in contact with the quartz crystal element, where x=t/T≥0.01, |φ−(−98.6x.sup.3+114.0x.sup.2−22.3x+1.3)|≤5 and |θ−(−9.5x.sup.3−10.9x.sup.2+1.4x+35.3)|≤0.5, wherein T is a thickness of the quartz crystal element and t is a thickness of the electrode.

A vibrator device includes a vibrator element having a base part, and a detection arm and a drive arm as a plurality of vibrating arms extending in a B direction as a first direction from the base part, a base body, and a support substrate configured to support the vibrator element with respect to the base body, wherein the support substrate includes a base-body fixation part to be fixed to the base body, an element support part configured to support the base part of the vibrator element, and a beam part configured to couple the base-body fixation part and the element support part to each other, and the support substrate has a plurality of recessed parts corresponding to the plurality of vibrating arms in an area which is located at a side of a surface opposed to the vibrator element, and on which at least a part of the vibrating arms overlaps in a plan view.

A vibrator device includes a vibrator element having a base part, and a detection arm and a drive arm as a plurality of vibrating arms extending in a B direction as a first direction from the base part, a base body, and a support substrate configured to support the vibrator element with respect to the base body, wherein the support substrate includes a base-body fixation part to be fixed to the base body, an element support part configured to support the base part of the vibrator element, and a beam part configured to couple the base-body fixation part and the element support part to each other, and the support substrate has a plurality of recessed parts corresponding to the plurality of vibrating arms in an area which is located at a side of a surface opposed to the vibrator element, and on which at least a part of the vibrating arms overlaps in a plan view.

A resonator device includes a quartz crystal substrate, a resonator element including a first excitation electrode arranged on a first surface of the quartz crystal substrate, a second excitation electrode arranged on a second surface of the quartz crystal substrate in opposition to the first excitation electrode, and first and second pad electrodes that are arranged on the first surface and are coupled to the first and second excitation electrodes, a base including a substrate and first and second interconnects arranged on the substrate, a first bonding member bonding the first pad electrode to the first interconnect, and a second bonding member bonding the second pad electrode to the second interconnect. The first and second bonding members are arranged such that a first imaginary line that passes through a centroid of the resonator element and is parallel to an X axis is interposed between the first and second bonding members. An angle θ1 formed between the first imaginary line and a second imaginary line passing through the first bonding member and the second bonding member is 100°<θ1<140°.

A resonator device includes a quartz crystal substrate, a resonator element including a first excitation electrode arranged on a first surface of the quartz crystal substrate, a second excitation electrode arranged on a second surface of the quartz crystal substrate in opposition to the first excitation electrode, and first and second pad electrodes that are arranged on the first surface and are coupled to the first and second excitation electrodes, a base including a substrate and first and second interconnects arranged on the substrate, a first bonding member bonding the first pad electrode to the first interconnect, and a second bonding member bonding the second pad electrode to the second interconnect. The first and second bonding members are arranged such that a first imaginary line that passes through a centroid of the resonator element and is parallel to an X axis is interposed between the first and second bonding members. An angle θ1 formed between the first imaginary line and a second imaginary line passing through the first bonding member and the second bonding member is 100°<θ1<140°.

A quartz crystal unit comprising a quartz crystal resonator having a base portion, and first and second tuning fork arms connected to the base portion, the base portion having a length less than 0.5 mm and greater than a spaced-apart distance between the first and second tuning fork arms, each of the first and second tuning fork arms having a width less than 0.1 mm and a length less than 1.56 mm, and a plurality of different widths including a first width and a second width greater than the first width, at least one groove being formed in at least one of opposite main surfaces of each of the first and second tuning fork arms so that a length of the at least one groove is within a range of 0.3 mm to 0.79 mm, the quartz crystal resonator being housed in a case, and a lid being connected to the case.

A quartz crystal unit comprising a quartz crystal resonator having a base portion, and first and second tuning fork arms connected to the base portion, the base portion having a length less than 0.5 mm and greater than a spaced-apart distance between the first and second tuning fork arms, each of the first and second tuning fork arms having a width less than 0.1 mm and a length less than 1.56 mm, and a plurality of different widths including a first width and a second width greater than the first width, at least one groove being formed in at least one of opposite main surfaces of each of the first and second tuning fork arms so that a length of the at least one groove is within a range of 0.3 mm to 0.79 mm, the quartz crystal resonator being housed in a case, and a lid being connected to the case.