Inkjet head comprising a substrate having pressure chambers, which contain ink, communicate with respective nozzles from which the ink is ejected in a predetermined direction. A spacer substrate is disposed on an opposite side of a diaphragm from the predetermined direction. The diaphragm forms one surface of each of the pressure chambers, which is on an opposite side of the each of the pressure chambers from the predetermined direction. A wiring substrate is disposed on an opposite side of the spacer substrate from the predetermined direction. Actuators are in contact with the diaphragm in a space formed by the spacer substrate between the wiring substrate and the diaphragm, the actuators being electrically connected to respective wires of the wiring substrate. Differences in coefficients of thermal expansion between the pressure-chamber substrate, the diaphragm, the spacer substrate, and the wiring substrate are equal to or less than a predetermined value.