Liquid ejection head and manufacturing method thereof

A liquid ejection head includes a print element substrate having an ejection port for ejecting a liquid; a support member supporting the print element substrate; and an adhesive agent provided for adhering the print element substrate to the support member. The print element substrate includes a supply port opposed to the support member and communicating with the ejection port, a first surface opposed to the support member and surrounding the supply port, and a second surface opposed to the support member and provided along at least a part of an outer edge of the first surface and retracted from the first surface relative to the support member. The adhesive agent is filled in a first space between the first surface and the support member, and at least a part of a second space between the second surface and the support member.