A piezoelectric actuator 3 includes a metallic vibration plate 30, an
insulating layer 31, a plurality of individual electrodes 32, a
piezoelectric layer 33 and a common electrode 34. The insulating layer 31
is formed on the top surface of the vibration plate 30. The individual
electrodes 32 are formed on the top surface of the insulating layer 31.
The piezoelectric layer 33 is formed on the top surfaces of the
individual electrodes 32. The common electrode 34 is formed on the top
surface of the piezoelectric layer 33 over the individual electrodes 32.
A plurality of terminals 36 and a plurality of wirings 35 are formed on
the top surface of the insulating layer 31. Each of the terminals 36 is
associated with one of the individual electrodes 32. Each of the wirings
35 connects one of the individual electrodes 32 and the associated
terminal 36.