To stabilize a supply voltage which is to be impressed to recording elements and control an ink discharge energy to be optimum in accordance with ink types and recording elements to meet high speeds and many nozzles.

An ink jet head is constituted including a predetermined voltage generation circuit 11 for supplying a voltage which is to be impressed to a heater to each of heating elements 13 of a heater group 12 formed on an element substrate. Since the predetermined voltage generation circuit 11 is set to the ink jet head 1, even if spiky noises overlap with an input voltage supplied from the outside to the ink jet head 1 or a voltage drop is brought about to the input voltage, an output voltage of the predetermined voltage generation circuit 11 is maintained to be almost constant. The voltage to be impressed to the heater which changes little to noise inputs and an external voltage drop can be impressed to each of the heating elements 13 accordingly.