PURPOSE: To enable the formation of drips stably at a high speed while reducing energy loss by a method wherein a fluid resistance element is arranged between a nozzle and a pressure chamber while a fluid flow smoothening element between the pressure chamber and an ink feed port with the direction of the pressure chamber set forward to make the resistance of the fluid resistance element higher than the resistance of the fluid flow smoothening element.

CONSTITUTION: When a voltage is applied to an electromechanical conversion means 2 from a driving means 7, a fluid flow smoothening element 5 comprising a check valve or the like for checking the flow in the direction of an ink feed port 4 is reversed and the ink extruded from a pressure chamber 3 is jetted in ink drips from a nozzle 1 passing through the fluid resistance element 6. Then, as the voltage changes to the original value, ink is sucked into the pressure chamber 3 with the pressure in the pressure chamber 3 becoming negative. Here, the less the forward resistance value of the fluid flow smoothening element 5 is than the resistance value of the fluid resistance element 6, the less the ink to be sucked into the pressure chamber 3 from the nozzle 1 side is. This can reduce the time required for the return to the initial condition to enable a high-speed operation thereby minimizing the energy loss spent on the operations other than the drip formation.