A liquid discharge head includes an Si substrate which is provided with an element for generating energy used in discharging a liquid and a liquid supply port which is provided to pass through the Si substrate from a first surface to a rear surface so as to supply a liquid to the element. A method of manufacturing the substrate includes: forming a plurality of concave portions on the rear surface of the Si substrate of which a plane orientation is {100}, the concave portions facing the first surface and aligned in rows along a direction of the Si substrate; and forming a plurality of the liquid supply ports by carrying out a crystal axis anisotropic etching on the Si substrate through the concave portions using an etching liquid of which an etching rate of the {100} plane of the Si substrate is slower than that of the {110} plane of the Si substrate.