A piezoelectric actuator includes: a buffer layer that is composed of an oxide or a nitride epitaxially formed on a Si substrate; a bottom electrode formed on the buffer layer, being composed of a transition metal oxide, and having a pseudo-cubic (100) or (111) orientation with a perovskite structure; a piezoelectric layer formed on the bottom electrode being composed of (Ba_1-xM_x)(Ti_1-yZ_y)O₃ (where (M=Sr or Ca and 0x0.3) (Z=Zr or Hf and 0y0.2)) with a pseudo-cubic (001) or (111) orientation; and a top electrode that is formed on the piezoelectric layer. In this way, a piezoelectric actuator that uses barium titanate as the piezoelectric body and does not include Pb is provided.