Patent ID: 7370940

Claim:
A liquid ejection head, comprising; an ejection port for ejecting a liquid; a flow passage communicating with said ejection port; a device substrate provided with a heating body for forming a bubble in said liquid filled in said flow passage; and a movable member provided on said device substrate in a state such that a first end thereof is fixed upon said device substrate and a free end at an opposite end of said movable member is in a freely movable state, said movable member being provided so as to face said heating body such that there is formed a gap between said movable member and said device substrate, said movable member causing a displacement upon ejection of said liquid from said ejection port as a result of a pressure caused by formation of said bubble, wherein said movable member is constructed by lamination of three or more layers, an end surface of at least one layer of said movable member being covered, at said free end, by another layer of said three or more layers.