Method for manufacturing laminated structure and method for manufacturing liquid ejection head substrate

A method for manufacturing a laminated structure, comprising:

• a step A of forming an electro-conductive material layer against an insulating layer provided on a substrate along with forming a wiring layer in a pattern with a resist layer laminated against the electro-conductive material layer as a mask;
• a step B of removing the resist layer along with removing a residue formed on a surface of the wiring layer at a same time;
• a step C of forming a mask layer on a surface of the substrate where the wiring layer is formed, wherein the mask layer covers at least the wiring layer and at least a part of a foreign matter not removed in the removing of the residue formed on a surface of the wiring layer;
• and
• a step D of performing an etching treatment on the surface of the substrate where the mask layer is formed, wherein in the step D, the at least the part of the foreign matter covered with the mask layer is removed selectively halfway in a thickness direction thereof;
• and
• a step E of forming a film forming layer with an electro-conductive material or a resin material on the surface of the substrate on which the wiring layer containing the foreign matter to which the step D is performed is formed, wherein the mask layer and the foreign matter are covered with the film forming layer without being exposed from the film forming layer.