Patent ID: 7543381

Claim:
A method of manufacturing a liquid ejection head, comprising: providing a first metal plate; supporting the first metal plate on a female die; forming a plurality of recesses in the first metal plate so as to be arrayed in a first direction; opposing a male die to the recess, the male die comprising a punch array in which a plurality of punches arrayed in the first direction; actuating the male die in a second direction perpendicular to the first direction to form a through hole at a bottom portion of each of the recesses with each of the punches; providing a second metal plate formed with a plurality of nozzle orifices; and joining the first metal plate and the second metal plate such that each of the nozzle orifices is communicated with one of the recesses, wherein: a contour line of the punch array defined by connecting respective distal end faces of the punches includes a plurality of parts assuming straight lines extending in the first direction; and one of straight lines which is closer to an end of the punch array is farther from the female die than one of the straight lines which is closer to a center of the punch array, in accordance with a warp of the plate member due to the formation of the recesses.