An inkjet head chip has an ink chamber containing ink, channels separated by piezoelectric elements and disposed parallel to each other along a width direction of the inkjet head chip, and a nozzle hole for discharging an ink droplet. The channels include a discharge channel disposed in a middle portion of the parallely disposed channels and communicating with the ink chamber and nozzle hole, dummy channels disposed outside of the discharge channel at respective ends thereof, and non-discharge channels toward the recording medium and supply of the ink from the ink chamber to the dummy channels is interrupted. The discharge of an ink droplet from the non-discharge channels toward the recording medium and the supply of ink from the ink chamber to the non-discharge channels are interrupted. The inkjet head chip is configured such that voltages are substantially simultaneously applied to one of the plurality of piezoelectric elements which is adjacent to the discharge channel and to one of the plurality of piezoelectric elements which is disposed between the dummy and non-discharge channels.