The properties of an ORN were also investigated via experiments. I used an electrochemical system such as that illustrated in Figure , in which two Pt electrodes (an anode (AN) and a cathode (CA)) and five Pt probes, made by using photolithography, are immersed in an acidic aqueous electrolyte containing redox couples. Applying a voltage between the AN and CA caused an electric current to flow in the redox electrolyte, and the five Pt probes measured the redox potential of the redox electrolyte at each position because the Pt probe and the redox electrolyte were in electron-transfer equilibrium. The electric current in the redox electrolyte flowed by electron-transfer reaction (or electron hopping) between a reductant R and an oxidant Ox in the electrolyte as well as by their diffusion. As explained later, the former process is the main contributor to the electric current. Therefore, when the redox electrolyte contains various redox couples, the electric current flows via the consecutive occurrence of electron-transfer reactions of type Ri + Oxj ⇌ Oxi + Rj, where subscripts i and j refer to the kind of redox couple. Thus, the redox couples in the redox electrolyte form an ORN in which source substances are supplied by electrode reactions at the AN and some reaction products are discharged at the electrode reactions at the CA, both at constant rates. We therefore expect that a nonequilibrium steady state is achieved in this system.