A cell cutting device that cuts a mother substrate for display devices includes a fixing unit configured to move in a state where the mother substrate for display devices is fixed on the fixing unit, a cutter configured to perform a cutting process on the mother substrate for display devices and the cutter faces a surface of the mother substrate during the cutting process, a cutter driving unit driving the cutter in a state where the cutter is fixed thereon, and a buffer member arranged on another surface of the mother substrate to correspond to the cutter. The other surface is opposite the surface facing the cutter.