Method for producing ethylene oxide

To provide a method for producing ethylene oxide, said method being capable of reducing the emission amount of carbon dioxide. [Solution] A method for producing ethylene oxide, said method comprising: an ethylene oxide production step 1 wherein a first mixture containing ethylene oxide is obtained by causing ethylene and oxygen to react with each other in the presence of a diluent gas; a gas-liquid separation step 2 wherein the first mixture is gas-liquid separated into a second mixture that contains ethylene, oxygen and carbon dioxide and a third mixture that contains ethylene oxide and water; a carbon dioxide separation step 3 wherein carbon dioxide is separated from the second mixture; and an electrolytic reduction step 4 wherein oxygen and a fourth mixture that contains ethylene, methane and carbon dioxide are obtained by electrolytically reducing the carbon dioxide. In the carbon dioxide separation step, carbon dioxide is separated from the fourth mixture. In the ethylene oxide production step, the secon