Method of producing liquid ejection head

A method of producing a liquid ejection head including an ejection port member having ejection ports through which liquid is ejected, and a flow-path-wall member having inner walls of liquid flow paths through which liquid is supplied to the ejection ports, the method comprising, in sequence, the steps of:

• preparing a substrate having the flow-path-wall member;
• bonding the flow-path-wall member to a resin layer that is composed of a photo-curing resin and serves as the ejection port member such that spaces serving as the flow paths are provided inside;
• providing through-holes in the resin layer such that the spaces communicate with the outside air;
• exposing part of the resin layer;
• heating the exposed portion of the resin layer;
• and
• removing the unexposed portion from the heated resin layer to form the ejection ports, thereby forming the ejection port member.