An ink jet print head comprises a substrate formed with a heating resistor, an ink path defining member for defining an ink supply path, and an orifice plate, and in the orifice plate, there is formed an ink outlet at the position opposing the heating resistor. Further, a heating zone surrounding the heating resistor is formed at the position corresponding to the heating resistor of the ink supply path. The channel resistance of the ink supply path is set so that a relationship is established between a quantity q of the discharged ink drop, a sectional area A of the ink outlet, and a maximal projection h that a meniscus of the ink has when it projects from the ink outlet after it has restored the exit level from a retreat position it had after the drop of the ink had been discharged such that 0