There is provided an ink jet head substrate which can sufficiently suppress generation of noises at the time when heating elements are driven, and which can be constituted small in size. In an ink jet head substrate including a plurality of heating elements, a power transistor for driving the heating elements according to image data, an input pad of a heat pulse (pulse width regulating signal) for regulating a width of a drive pulse to be applied to the heating elements, and a block selection unit for dividing the plurality of heating elements into blocks for a predetermined number of heating elements to drive the heating elements in a time division manner with the divided block as a unit, a delay circuit group consisting of a logic circuit (delay circuit) for supplying a drive pulse, which is applied to the heating elements in a selected block, at staggered timing is provided in a line of a heat pulse.