An electrode sheet disposed in a touch input device capable of detecting a pressure of a touch on a touch surface may be provided. The touch input device includes: a display module; a pressure electrode disposed under the display module; and a reference pressure electrode disposed under the display module. A distance between the pressure electrode and a reference potential layer is changed when the pressure is applied to the touch surface. A capacitance detected at the pressure electrode is changed according to the distance change. A magnitude of the pressure applied to the touch surface is calculated on the basis of a difference between a reference capacitance calculated from a capacitance detected at the reference pressure electrode and a detected capacitance calculated from the capacitance detected at the pressure electrode.