PURPOSE: To adjust the phase of injected ink by a simple control means and to compensate the scatter of nozzles caused by preparation by providing a passage resistance variable element between the nozzle of ink jet head and the pressure cell.

CONSTITUTION: The jet head is composed of the pressure cell 31, nozzle 32 and passage 33. An electrostriction element 34 is placed in the midway of the passage, the element 34 can be deformed as shown by the dotted line by giving an electric field to the element to change the cross-sectional area of the passage. For the passage resistance variable element, a magnetostriction element or a valve 35, which can be controlled from the outside, can be used in place of the electrostriction element 34.