A method of producing a liquid ejection head includes preparing an element substrate including energy generating elements for generating energy and connecting terminals electrically connected to the energy generating elements, an electrical wiring member including lead wires electrically connected to the connecting terminals, and a support member supporting the element substrate and has a recess for accommodating the element substrate and a protrusion protruding inward from an inner surface of the recess; providing adhesive on a bottom surface of the recess, positioning the element substrate in the recess and pressing the adhesive to introduce a portion of the adhesive into a space between the protrusion and the element substrate, and sealing a connected portion of the connecting terminals and the lead wires with a sealing material, the sealing material being prevented from flowing by a portion of the adhesive filling the space between the protrusion and the element substrate.