Patent ID: 7100415

Claim:
A method of manufacturing a liquid ejection head which ejects liquid droplets by generating pressure fluctuation in liquid contained in a plurality of pressure generating chambers communicated with a common liquid reservoir, the method comprising steps of: providing a metallic plate member having at least one through hole to be a part of the common liquid reservoir; providing a first die, in which a plurality of first projections are arrayed in a first direction with a fixed pitch, each of the first projections being elongated in a second direction perpendicular to the first direction; providing a second die, on which the plate member is mounted; inserting a regulating member into the through hole; and performing a first forging work in which the first projections are pressed against a first region in a first face of the plate member which is adjacent to the through hole in the second direction, the first projections being pressed in a third direction orthogonal to the first direction and the second direction, so as to generate a plastic flow of a material in the plate member into gaps defined between the first projections, while the plastic flow is regulated by the regulating member, wherein a plurality of recesses formed by the first projections and a plurality of partition walls formed by the material flown into the gaps constitutes a part of the pressure generating chambers.