The invention relates to a method for continually producing 1,3-dioxolan-2-ones such as ethylene carbonate or propylene carbonate by reacting a corresponding oxirane with carbon dioxide in liquid phase in the presence of a catalyst. The reaction is carried out in a two-part reactor. In the first part of the reactor, the reaction is carried out with back-mixing until a conversion rate of oxirane II of at least 80 % has been reached. In the second part, the reaction is completed under conditions without back-mixing, the carbon dioxide being guided to the oxirane II in a counterflow throughout the reactor.