An ink jet printer head having nozzles, actuators, a multiplexer, and actuator finding circuits of a matrix method. The multiplexer is capable of single-input and multiple output. The actuator finding circuits of the inkjet printer head include electronic switches arranged in rows and columns. The nozzles have the actuators, and the actuators are controlled by the electronic switches. The multiplexer receives a signal in accordance with the conveyance direction and position of the ink jet printer head, and sequentially outputs the signal to the actuator finding circuits in accordance with the signal it received, thereby sequentially selecting a nozzle group in the rows. In this situation, when an external print data signal is inputted to the actuator finding circuits to select a nozzle group in the columns, the corresponding electronic switch drives the actuator, so that the ink is ejected out of the nozzle. Accordingly, by using the multiplexer having only one external input terminal, the increment of the number of pads is decreased when the number of ink jet printer head nozzles is increased.