A vibration element includes a piezoelectric substrate including a vibrating section and a thick section having a thickness larger than that of the vibrating section. The thick section includes a first thick section provided along a first outer edge of the vibrating section, a second thick section provided along a second outer edge thereof, and a third thick section provided along a third outer edge thereof. When a maximum size of the second thick section in the vibration direction is Lmax and a minimum size thereof is Lmin, an average size expressed by (Lmax+Lmin)/2 is 100 μm or smaller.