Patent ID: 8376522

Claim:
A liquid ejection head comprising: a substrate in which a plurality of heat generation elements for generating thermal energy used for ejecting a liquid are arranged at a surface; a flow path supplying liquid to be ejected; an energy application chamber formed by i) the surface of the substrate in which at least one of the heat generation elements is arranged and ii) a chamber wall provided on the surface of the substrate and including a communication portion through which the flow path and the energy application chamber are in communication with each other on the surface of the substrate; an ejection port portion including an ejection port for ejecting the liquid to which thermal energy is applied by the at least one heat generation element, formed at a position opposite to the heat generation element, and the ejection port portion enabling communication between the ejection port and the energy application chamber; and a partition wall, formed at a position opposite to the ejection port, at least partially formed inside of an area, in which the at least one heat generation element is arranged, on the surface of the substrate, wherein a distance from the surface of the substrate to a farthest position of the partition wall from the surface of the substrate is at least substantially half the height of the energy application chamber in a liquid ejection direction in which the liquid is ejected, and is no more than the height of the energy application chamber in the liquid ejection direction, and wherein no wall is arranged between the chamber wall and the partition wall.