In a method and a device according to the present invention, two piezo-elements of a piezo-electric actuator are driven with two voltages having a mutual phase difference. One of said piezo-elements is charged by a capacitive voltage step-up means to a voltage exceeding an available power supply voltage. A capacitor is coupled to the piezo-element, which divides the voltage of the piezo-element and simultaneously transfers part of the energy stored in the piezo-element to said capacitor. A part of the energy transferred to said capacitor is later transferred back to said piezo-element, providing an energy-saving feature. The second piezo-element is driven in a similar way providing the required phase difference. In a further embodiment, the waveforms of the two driving signals are corrected using balancing capacitors.