A method for driving a liquid ejector (1) provided with a piezoelectric actuator (7) including a piezoelectric ceramic layer (6) having a size covering a plurality of pressurizing chambers (2). An arbitrary piezoelectric deformation region (8) of the liquid ejector (1) is deflected in one thickness direction and the opposite direction individually by applying a driving voltage waveform including a first voltage (−VL) and an equivalent second voltage (+VL) of the opposite polarity in order to vary the volume of the pressurizing chambers (2) of a corresponding liquid droplet ejecting portion (4), and a liquid droplet is ejected through a communicating nozzle (3). Since gradual creep deformation of the inactive region (16) of the piezoelectric ceramic layer (6) is prevented, the ink droplet ejection performance is maintained at a good level over a long period.