A spraying device for introducing a fluid into the working chamber of a construction machine for processing ground or road surfaces comprises at least one outlet nozzle by which the fluid is introduced into the working chamber, a line system by which the fluid is conveyed to the at least one outlet nozzle, and a control unit by which the fluid supply to the outlet nozzle is controllable. The present invention further relates to a construction machine for processing ground or road surfaces, especially a milling machine for milling off road or ground surfaces, a stabilizer for stabilizing ground of low bearing capacity and a recycler for repairing pavements in need of repair, comprising such a spraying device, and a method for operating a working device of such a construction machine.