A manufacturing method for manufacturing a liquid ejection element including a liquid flow path which is open at an ejection outlet for ejecting liquid, and an energy generating member for generating energy usable for ejecting the liquid from liquid flow path through the ejection outlet, the manufacturing method, includes a step of forming the energy generating member on a front side of a substrate; a step of forming a top plate member on the side having the energy generating member formed by the energy generating member forming step, wherein the top plate member is a member in which the liquid flow path and the ejection outlet are formed; and a step of thinning the substrate, having the top plate member formed thereon by the top plate member forming step, from a back side thereof.