A crystallographically-oriented ceramic including first regions, in which
crystal nuclei remain and which contain a specific element in a
predetermined concentration range and extend at least partially in a
layered shape along a crystal plane, and second regions, which contain
the specific element in a different concentration range from the first
regions and extend at least partially in a layered shape along the
crystal plane. The regions are alternately repeated, and a compositional
distribution exists in a direction orthogonal to the crystal plane. In
the first region, the concentration of Na is higher, the concentration of
K is lower, the concentration of Nb is lower, and the concentration of Ta
is higher than the second region, and in the second region, the
concentration of Na is lower, the concentration of K is higher, the
concentration of Nb is higher, and the concentration of Ta is lower than
the first region.