METHOD FOR MANUFACTURING LIQUID EJECTION HEAD

PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid ejection head that can reduce manufacturing cost.SOLUTION: The method for manufacturing the liquid ejection head includes a protective film forming step of forming a protective film 16 on a wall surface part located in a liquid flow path after a reservoir forming substrate wafer 130 having a reservoir part 31 comprising part of a reservoir to form a liquid chamber and a conductive connection wiring 200 and a flow path forming substrate wafer 110 having a liquid flow path including a communicating part 13 comprising the reservoir communicating with the reservoir part 31 and a wiring layer 190 for blocking a part between the reservoir part 31 and the communicating part 13 are in a connected state. The method adopts a penetration step of penetrating the wiring layer 190 prior to the protective film forming step and a coating film forming step of forming a coating film 140 for coating the connection wiring 200.