A liquid injection nozzle including a substantially planar substrate having first and second opposed surfaces. A communicating portion, which has an inner circumferential surface, extends through the substrate from the first surface to the second surface of the substrate. The inner circumferential surface is tapered from the first surface toward the second surface such that a lateral dimension of the inner circumferential surface is narrowest at a tip portion. A projected part extends from the second surface of the substrate and defines the tip portion which terminates the communicating portion.