A sensor element for an angular velocity sensor comprising: a plurality of first electrodes and a plurality of second electrodes; and a piezoelectric body, wherein the piezoelectric body, when viewed in a z-direction in an orthogonal coordinate system xyz and wherein widths are defined as lengths in the x-direction, comprises a base part; two first arms (23A-D) which extend alongside each other from the base part to one side in a y-direction and on which the plurality of first electrodes are located; two second arms (25A, 25B) which extend alongside each other from the base part to the other side in the y-direction and on which the plurality of second electrodes are located, wherein each of the two second arms (25A, 25B) comprises a body portion which extends from the base part to the other side in the y-direction and a broad width portion which is positioned at an end of the body portion furthest from the base part, and is broader in width than the body portion, and whereby a distance between the two second arms becomes shorter at the broad width portions than at the ends of the second arms closest to the base part; a mounting part which is connected to an end part of a holding part on the other side in the y-direction; and the holding part, which extends between the two second arms from the base part to the other side in the y-direction and extends out beyond the two second arms to the other side in the y-direction, comprises a main portion extending from a position between the broad width portions of the two second arms to a side where the base part is located while maintaining a width not less than a width of its portion located between the broad width portions of the two second arms and a connection portion which is connected to the main portion and the base part, the connection portion being broader in width than the main portion; characterized in that a width of the connection portion is longer than a distance between the broad width portions. a plurality of first electrodes and a plurality of second electrodes; and a piezoelectric body, wherein the piezoelectric body, when viewed in a z-direction in an orthogonal coordinate system xyz and wherein widths are defined as lengths in the x-direction, comprises a base part; two first arms (23A-D) which extend alongside each other from the base part to one side in a y-direction and on which the plurality of first electrodes are located; two second arms (25A, 25B) which extend alongside each other from the base part to the other side in the y-direction and on which the plurality of second electrodes are located, wherein each of the two second arms (25A, 25B) comprises a body portion which extends from the base part to the other side in the y-direction and a broad width portion which is positioned at an end of the body portion furthest from the base part, and is broader in width than the body portion, and whereby a distance between the two second arms becomes shorter at the broad width portions than at the ends of the second arms closest to the base part; a mounting part which is connected to an end part of a holding part on the other side in the y-direction; and the holding part, which extends between the two second arms from the base part to the other side in the y-direction and extends out beyond the two second arms to the other side in the y-direction, comprises a main portion extending from a position between the broad width portions of the two second arms to a side where the base part is located while maintaining a width not less than a width of its portion located between the broad width portions of the two second arms and a connection portion which is connected to the main portion and the base part, the connection portion being broader in width than the main portion; characterized in that a width of the connection portion is longer than a distance between the broad width portions.