In a pure ethylene oxide distillation process, an aqueous mixture containing ethylene oxide, formaldehyde and at least 5 % by weight water is supplied via an inlet to a distillation device with at least one distillation column at a height above the column bottom of at least 8 theoretical stages. The ethylene oxide is removed at the head of the column and a mixture is obtained at the bottom of the column with less than 5 % by weight ethylene oxide.
