To provide a piezoelectric vibrating piece capable of preventing short circuit at the time of mounting caused by miniaturization. In a piezoelectric vibrating piece having a support arm portion provided with mount electrodes between a pair of vibrating arm portions, a layout wiring connected to the first mount electrode on the base end side of the support arm portion is formed on a mount surface, and at least a layout wiring passing the vicinity of the first mount electrode in the layout wirings connected to the second mount electrode on the tip side of the support arm portion is formed on an opposite mount surface side, thereby preventing short circuit of a conductive adhesive for bonding the first mount electrode to an electrode on the package side with respect to the layout wiring on the second mount electrode side.