PURPOSE: To efficiently regenerate a catalyst, containing a bivalent copper compound and having the deteriorated activity, enable repeated use thereof and obtain a carbonic acid ester by reacting an alcohol with carbon monoxide and oxygen.

CONSTITUTION: An alcohol is made to react with carbon monoxide and oxygen in the presence of a catalyst comprising a bivalent copper compound to produce the objective carbonic acid ester. In the process, the catalyst having the deteriorated activity in the reactional solution is regenerated by replacing the reactional solution or concentrated solution with water until the concentration of an organic component (the alcohol, carbonic acid ester, etc.) in the reactional solution attains ≤5%, preferably ≤2%, then heat-treating the resultant solution at 150-1000°C temperature and subsequently treating the heat-treated solution with a weak acid. A bivalent copper compound or a combination system thereof with a palladium compound is cited as the catalyst.