PURPOSE: To attain the improvement of quality, performance and yield of printing by equalizing the speeds of ink droplets in a multi-nozzle printing head by a pass-through etching process.

CONSTITUTION: The depth of sectional flow paths of a nozzle 101 and a communication path 102 depends on the thickness of a nozzle plate 205, and the aspect ratio of the cross section is nearly 1. Even when the cross section of the flow path is the same as that of the nozzle 101 in the case of half-etching process, the resistance of flow path becomes smaller and the repeating frequency of ink droplets jet is raised. The width of the nozzle 101 is also made smaller. The integrity of the multi-nozzle can thus be raised. Since dimensional error by a pass- through etching process is much smaller than that by half-etching process, the speeds of ink dropletes to be jetted from the multi-nozzle can be equalized and the quality of printing can be raised.