Abstract: A method and an apparatus are provided for stopping a motor-driven pressure generating pump of a system for coating workpieces with atomized liquid coating material in case of an empty material reservoir or a leakage in a material supply from a material reservoir to the pump or from the pump to an atomizer. The pressure and/or the volume flow at the pump outlet and/or the speed of the pump piston or a value dependent thereon are continually measured. The measured values are then converted to electric signals to be input to an electronic analyzer and analyzed therein. If, during operation, the pressure and/or the volume flow drops below a predetermined value and/or the speed of the piston exceeds a predetermined value, the electrically controlled driving connection between motor and pump or the power supply to the pump motor will be cut-off by output signals from the electronic analyzer.