The invention provides a piezoelectric vibrating piece and piezoelectric device, suppresses vibration, and prevents loss of vibration energy during frequency adjustment. The piezoelectric vibrating piece includes a piezoelectric substrate, a first excitation electrode, and a second excitation electrode. The piezoelectric substrate is formed into a flat plate shape and vibrates in a thickness-shearvibration mode. The first excitation electrode is formed on one principal surface of the piezoelectric substrate. The second excitation electrode is formed on another principal surface of the piezoelectric substrate. The first excitation electrode is formed to entirely have an identical thickness. The second excitation electrode has a main thickness portion and an inclined portion. The main thickness portion has a constant thickness. The inclined portion is formed in a peripheral area of the main thickness portion and gradually decreases in thickness from a portion in contact with the main thickness portion to an outermost periphery of the second excitation electrode. The main thickness portion has a thickness larger than the thickness of the first excitation electrode.