An electrochemical system for synthesizing an oxidizing agent solution from water and a sodium chloride solution, comprising: a diaphragm electrolysis apparatus with a tubular ceramic ultrafiltration diaphragm, a circulation circuit for the catholyte and anolyte, with corresponding separation vessels (10, 21) for separating the electrolysis gases and with heat exchanger devices for cooling the catholyte and anolyte, a device for feeding aqueous salt solution into an anode compartment of the diaphragm electrolysis apparatus under pressure, said device consisting of a metering pump with a vessel for dissolving the salt, a device for dissolving moist gaseous products of the electrochemical anode reactions in a fresh water stream to obtain an oxidizing agent solution, a device for stabilizing the overpressure in the anode compartment, a collection vessel for the oxidizing agent solution, and a means for metered feed of the catholyte from the separation vessel of the cathode circuit into the oxidizing agent solution to be synthesized, characterized in that a filter is arranged in a feed line feeding the fresh water to the device for dissolving moist gaseous products of the electrochemical anode reactions, the means for metered feed of catholyte from the separation vessel of the cathode circuit into the water stream which is flowing to the filter is installed in a fresh water feed line upstream of the filter, and wherein the dissolution of the salt in the vessel of the device for feeding aqueous salt solution into the anode compartment in the oxidizing agent solution proceeds using a means for metered feeding of the oxidizing agent solution from the collection vessel for the oxidizing agent solution into the vessel for dissolving the salt, at the outlet of which a filter is arranged which is connected to the inlet of the metering pump for feeding the salt solution under pressure into the anode compartment of the electrolysis apparatus. a diaphragm electrolysis apparatus with a tubular ceramic ultrafiltration diaphragm, a circulation circuit for the catholyte and anolyte, with corresponding separation vessels (10, 21) for separating the electrolysis gases and with heat exchanger devices for cooling the catholyte and anolyte, a device for feeding aqueous salt solution into an anode compartment of the diaphragm electrolysis apparatus under pressure, said device consisting of a metering pump with a vessel for dissolving the salt, a device for dissolving moist gaseous products of the electrochemical anode reactions in a fresh water stream to obtain an oxidizing agent solution, a device for stabilizing the overpressure in the anode compartment, a collection vessel for the oxidizing agent solution, and a means for metered feed of the catholyte from the separation vessel of the cathode circuit into the oxidizing agent solution to be synthesized, characterized in that a filter is arranged in a feed line feeding the fresh water to the device for dissolving moist gaseous products of the electrochemical anode reactions, the means for metered feed of catholyte from the separation vessel of the cathode circuit into the water stream which is flowing to the filter is installed in a fresh water feed line upstream of the filter, and wherein the dissolution of the salt in the vessel of the device for feeding aqueous salt solution into the anode compartment in the oxidizing agent solution proceeds using a means for metered feeding of the oxidizing agent solution from the collection vessel for the oxidizing agent solution into the vessel for dissolving the salt, at the outlet of which a filter is arranged which is connected to the inlet of the metering pump for feeding the salt solution under pressure into the anode compartment of the electrolysis apparatus.