The present invention is a piezoelectric actuator unit 29 having piezoelectric vibrators 33 vibrating in the lamination direction of electrode layers and piezoelectric material layers which are alternately laminated. The piezoelectric vibrators are arranged in one row in the direction of vibrator arrangement perpendicular to the lamination direction. Each of the piezoelectric vibrators includes the area on one side and the area on the other side in the direction of the vibrator width perpendicular to the lamination and vibrator arrangement directions, and either of the area on one side and the area on the other side forms active parts capable of performing piezoelectric deformation, and the other area forms inactive parts incapable of performing piezoelectric deformation, and in the adjacent piezoelectric vibrators, the arrangement of the active part and inactive part is opposite. According to the present invention, the number of nozzles of the liquid ejecting apparatus can be increased without any inconveniences.