Provided is a crystal element that includes: a crystal piece that is in a substantially rectangular shape on a plan view; an excitation electrode part located on both main surfaces of the crystal piece; a connection lead part extended to a first short-side of the crystal piece from the excitation electrode part; a convex part located on both ends of a second short-side of the crystal piece; and a projected part located on both ends of the first short-side of the crystal piece. Further, a concave part is located in the convex part, and a recessed part is located in the projected part.