A liquid discharge head substrate is provided. The head substrate comprises a substrate, an insulator arranged above the substrate, conductive patterns arranged in the insulator, a heat generating resistive element arranged above the insulator, a protective layer covering the heat generating resistive element, and electrode plugs configured to connect the heat generating resistive element and the conductive patterns. The heat generating resistive element and the electrode plugs are arranged in contact with each other to overlap each other. A current flows through the heat generating resistive element in a first direction. In the first direction, a length of the electrode plug is smaller than a length of the heat generating resistive element and in a second direction crossing the first direction, a length of the electrode plug is larger than a length of the heat generating resistive element.