Liquid ejection head and method of manufacturing liquid ejection head

Provided are a liquid ejection head capable of preventing deformation and breakage of a filter and a method of manufacturing the liquid ejection head. The liquid ejection head comprises: a substrate comprising a supply port through which to supply a liquid and an element configured to produce energy for ejecting the liquid; a resin layer comprising an ejection port through which the liquid is ejectable with the energy produced by the element, and a flow channel connecting the supply port and the ejection port; a filter disposed between the supply port and the flow channel; and a support portion supporting a surface of the filter on the supply port side and a surface of the filter on the flow channel side.