Liquid ejection head and method of manufacturing the same

A method of manufacturing a liquid ejection head by forming an ejection port forming member for configuring an ejection port for ejecting liquid by using a photosensitive resin layer on a surface of a substrate, the method comprising:

• (1) a step of forming a dent representing a substantially spherical profile in a region including the position for forming the ejection port on a surface of the photosensitive resin layer;
• (2) a step of forming a latent image corresponding to the ejection port in the dent by way of an exposure treatment using a projection lens system;
• and
• (3) a step of producing the ejection port by developing the latent image;
• the latent image being formed by a beam of exposure light refracted by the projection lens system and inclined from the direction perpendicular to the surface of the substrate in the exposure treatment in the above-described step (2);
• the center of a top surface of the latent image being shifted to the incoming side of the beam of exposure light from the lowest point of the dent.