An ink jet printing head includes: a plurality of piezoelectric actuators arranged in rows on a substrate, each row including first piezoelectric elements and second piezoelectric elements which are alternately arrayed along the row, the first piezoelectric elements being actuatable to apply a compressive force to ink in accordance with print signals, the second piezoelectric elements being fixed and not actuated; and an ink chamber unit which includes ink chambers located above the first piezoelectric elements and containing ink. The ink chamber unit includes: an oscillation plate including diaphragm portions which are connected to the first piezoelectric elements and independently deformable in a direction perpendicular to the substrate by the first piezoelectric elements when actuated; and a nozzle plate which includes nozzles being located above the diaphragm portions and opened to the ink chambers, so that ink drops are respectively forced out from the nozzles when the first piezoelectric elements are actuated.