Substrate for ink jet head and ink jet head

A substrate for an ink jet head provided with a plurality of energy generating members which generate energy used for discharging an ink,

• wherein the plurality of energy generating members are provided in a row in a longitudinal direction of the substrate,
• the substrate has an electrode pad which is arranged near a side of the substrate extending in an intersecting direction intersecting with respect to the longitudinal direction, and is for electrically connecting to an outside of the substrate, a plurality of electrode wirings for electrically connecting the plurality of energy generating members and the electrode pad, and a plurality of resistance elements which are respectively provided at the plurality of electrode wirings,
• each of the plurality of electrode wirings includes a first portion extending in the longitudinal direction from a side of the electrode pad of each of the electrode wirings, and a second portion which extends in the intersecting direction from a side of the first portion opposite from the side of the electrode pad toward the energy generating members and is provided with the resistance elements, and
• resistance values of the plurality of resistance elements differ from one another according to resistance values of the electrode wirings provided with the respective resistance elements.