To produce a dialkyl dicarbonate using an easy-to-bauble alkyl alcohol and alkali metal carbonate, as starting substance.

An alkyl alcohol such as t-butanol is reacted with an alkali metal carbonate under pressure by carbon dioxide to produce an alkali metal monoalkyl carbonic acid ester. The compound is reactied with an aromatic sulfonyl halide in the presence of a tertiary amine under pressure by carbon dioxide to give the objective dialkyl carbonate such as di-t-butyl carbonate.