Liquid ejection head

A liquid ejection head comprising:

• a recording element substrate for ejecting liquid;
• a support member for supporting the recording element substrate;
• an adhesive layer provided between the recording element substrate and the support member;
• a first electrically connecting portion provided at an end portion of the recording element substrate;
• and
• a sealing member covering the end portion of the recording element substrate including the first electrically connecting portion,
• wherein the sealing member is in contact with a side surface of the end portion of the recording element substrate and an end surface of the adhesive layer,
• wherein the adhesive layer comprises:
• a first adhesive portion;
• and
• a second adhesive portion positioned between the first adhesive portion and the sealing member, and
• further wherein a first adhesive agent constituting the first adhesive portion and a second adhesive agent constituting the second adhesive portion are both thermally curable materials, and a curing temperature of the second adhesive agent is lower than a curing temperature of the first adhesive agent.