A method of manufacturing a liquid-discharge-head substrate is provided, which includes a plurality of elements for discharging liquid, and a heating member for heating the liquid-discharge-head substrate, the method including the steps of preparing a substrate having an insulating layer made of an insulating material provided on or above the substrate, providing a conductive layer made of a conductive material, and forming a conductive line being configured to supply current for driving the element and a part of a heating member by using the conductive layer.