A method of manufacturing a liquid ejecting head has a first molding step, a step of performing positioning and a second molding step. In the first molding step, a first member, a second member, and a third member are molded by injecting a resin at different locations inside of a set of a fixed mold, an intermediate movable mold, and a movable mold. In the step of performing positioning, the set is detached in a first direction and the intermediate movable mold and the movable mold are moved in a second direction. In the second molding step, a resin is injected to the inside of the set that is clamped to bond. During a period from the first molding step to completion of the second molding step, the first member, the second member, and the third member are held by insert mold pieces used for molding the members, respectively, in the first molding step.