An actuator element has a plate member, a piezoelectric/electrostrictive
body disposed in facing relation to the plate member, and a beam disposed
between the plate member and the piezoelectric/electrostrictive body and
fixing the piezoelectric/electrostrictive body to the plate member. The
piezoelectric/electrostrictive body has a piezoelectric/electrostrictive
layer, an upper electrode formed on a surface of the
piezoelectric/electrostrictive layer which faces the plate member, and a
lower electrode formed on a surface of the piezoelectric/electrostrictive
layer which is opposite to the surface thereof facing the plate member.
When an electric field is applied to the upper electrode and the lower
electrode, a portion of the piezoelectric/electrostrictive body is
displaced toward or away from the plate member.