A manufacturing method, for a liquid discharge head substrate that includes a silicon substrate in which a liquid supply port is formed, includes the steps of: preparing the silicon substrate, on one face of which a mask layer, in which an opening has been formed, is deposited; forming a first recessed portion in the silicon substrate, so that the recessed portion is extended through the opening from the one face of the silicon substrate to the other, reverse face of the silicon substrate; forming a second recessed portion by performing wet etching for the substrate, via the first recessed portion, using the mask layer; and performing dry etching for the silicon substrate in a direction from the second recessed portion to the other face.