A piezoelectric actuator is provided, including a piezoelectric layer arranged on one surface of a base member; a plurality of driving electrodes arranged on one surface of the piezoelectric layer; a plurality of leading electrodes led from the driving electrodes to apply a voltage to the driving electrodes; and a low dielectric layer arranged between the piezoelectric layer and the leading electrode, and having a dielectric constant lower than that of the piezoelectric layer. Surroundings of driving areas of the piezoelectric layer including areas facing the plurality of driving electrodes are joined to the base member. The plurality of leading electrodes extend to outside of the driving areas, respectively, some of the plurality of leading electrodes being led in a predetermined first direction, and others of the plurality of leading electrodes being led in a second direction different from the first direction.