A method for manufacturing a liquid ejection head having an ejection port-forming member in which an ejection port configured to eject liquid is formed, includes the steps of preparing a substrate including a base substrate; a first layer composed of a resin composition not containing a polymerization initiator but containing a compound that can be polymerized by irradiation with active energy rays under the presence of the polymerization initiator; and a second layer composed of an active energy ray-curable resin composition containing the polymerization initiator; pressing a mold, on which a pattern of the ejection port has been formed, against the first layer and the second layer; irradiating the second layer with the active energy rays while the mold is being pressed against the first layer and the second layer; bonding the second layer to another supporting substrate; and detaching the base substrate.