To obtain an aliphatic carbonic acid diester in a high yield and a high selectivity by reacting a urea and an aliphatic alcohol in the presence of a specific catalyst without using phosgene or CO gas having a high toxicity.

This method for producing an aliphatic carbonic acid diester is to react a urea of formula I [R1 to R4 are each H or a 1-18C hydrocarbon (may contain a hetero atom)] with an aliphatic alcohol of formula II [R5 is a 1-18C hydrocarbon (may contain a hetero atom)] in the presence of a catalyst consisting of a single material of an alkali metal or a compound thereof, to obtain an aliphatic carbamate of formula III or an aliphatic carbonic acid diester of formula IV, and also react the aliphatic carbamate of the formula III with the aliphatic alcohol of the formula II in the presence of the simple substance of the alkali metal or the compound thereof, to obtain the aliphatic carbonic acid diester of the formula IV. As the simple substance of the alkali metal used as a catalyst, Li, Na, K, Rb, Cs, Fr, etc., can be cited.