A piezoelectric actuator includes a vibration plate which is joined to a flow passage unit to cover a pressure chamber formed in the flow passage unit, a piezoelectric layer arranged on the vibration plate, a first electrode arranged on the piezoelectric layer to face the pressure chamber, a second electrode arranged on the piezoelectric layer while being opposed to the first electrode, and a third area arranged in the remaining area of the piezoelectric layer opposed to the pressure chamber. A first portion of the piezoelectric layer interposed by the first and second electrodes is polarized in parallel to the thickness direction. A second portion of the piezoelectric layer disposed between the first and third electrodes in the plane direction, is polarized in parallel to the plane direction. Accordingly, there are provided the piezoelectric actuator having a high driving efficiency.