An ink jet head is manufactured by joining together a cavity unit and an actuator unit. The cavity unit has a plurality of nozzles and a plurality of pressure chambers. The actuator unit has a plurality of piezoelectric elements. The cavity unit is joined to the actuator unit such that each of the piezoelectric elements is located to face a corresponding pressure chamber. A method of manufacturing the ink jet head includes a step of defining a relation between an average nozzle diameter of a cavity unit and an average capacitance of an actuator unit. The method also includes a step of measuring the average nozzle diameter of each of cavity units and a step of measuring the average capacitance of each of actuator units. A matching cavity unit and actuator unit are selected to satisfy the relation defined in the defining step, and the selected cavity unit and the selected actuator unit are joined together.