A method of manufacturing an inkjet head includes: forming an inlet and a pressure chamber in an upper substrate, the inlet penetrating the upper substrate and providing a passage for an inflow of ink, and the pressure chamber formed as a recess in one side of the upper substrate; forming a manifold and an ink channel in a middle substrate, the manifold configured to be connected with the inlet, and the ink channel penetrating the middle substrate and configured to be connected with the pressure chamber; forming a straight portion and a nozzle in a plate substrate, the straight portion configured to be connected with the ink channel, and the nozzle connected with the straight portion; forming a hydrophobic layer on one side of the plate substrate, the hydrophobic layer having a window formed therein, and the window opening the nozzle by a circumference greater than a circumference of an end of the nozzle; and stacking in order and attaching the upper substrate, the middle substrate, and the plate substrate.