A method of manufacturing a liquid ejecting method includes: a first step of injection molding passage members collectively constituting a passage for a liquid in the liquid ejecting head; a second step of moving the passage members to bring the passage members into contact with each other; and a third step of injecting a sealing material into a space between the passage members held in contact with each other, and filling the space with the sealing material. The sealing material is injected and filled, from a gate on a longitudinal side of the passage members, in a direction intersecting with a longitudinal direction of the passage members.