An embodiment of this invention relates to an element substrate that implements size reduction of the element substrate and simplification of the arrangement as well as a highly-reliable print operation, a printhead using the same, and a printing apparatus including the printhead. In the element substrate according to this embodiment, the slope of a ramp wave is changed to generate a plurality of pulses using one reference voltage. The slope of the ramp wave can be changed by changing the mirror ratio or the capacitance of a comparator as well as by changing the resistance of a DAC.