The invention relates to an electrochemical measuring cell for measuring the content of chlorine compounds in water, having an electrolyte chamber (2) which receives an electrolyte, a measuring electrode (3) which delimits the electrolyte chamber, a reference electrode (5), and a counterelectrode (4). Said electrochemical measuring cell is characterised in that the measuring electrode (3) is a rigid, porous platinum membrane having a pore size of 0.15 μm to 0.25 μm, which produces the contact with the electrolyte and the water.