Liquid ejection head manufacture method and liquid ejection head

When a filter for example is provided in a liquid supply path in the manufacture of a liquid ejection head, the filter can be prevented from being displaced or deformed. A manufacture method of a liquid ejection head having a liquid ejection unit for ejecting liquid and a liquid supply unit for supplying liquid to the liquid ejection unit has a processing of abutting a filter to a melting unit provided in the liquid supply unit and applying heat to the melting unit via the filter to melt the melting unit to thereby fix the filter to the melting unit, and a processing of burying the melting unit fixed to the filter by molding material.