The electrochemical reduction of CO2 at the Cu electrode was investigated in methanol-based electrolyte using various cesium supporting salts as the ionophore at an extremely low temperature (243 K). Cesium acetate, chloride, bromide, iodide, and thiocyanate were used as the ionophore. The main products from CO2 by electrochemical reduction were methane ethylene, ethane, carbon monoxide, and formic acid. In the methanol-based electrolyte using cesium supporting salts, except for acetate, the Faradaic efficiency for ethylene was larger than that for methane. This research can contribute to large-scale manufacturing of petrochemical intermediate products, such as methane and ethylene from readily available and cheap raw materials: CO2-saturated methanol from industrial absorbers (the Rectisol process). Thus the synthesis of hydrocarbons by the electrochemical reduction of CO2 may be of practical interest for fuel production, storage of solar energy, and production of intermediate materials for the petrochemical industry.