Abstract: A carbonic acid diester is produced at a high stability and selectivity by catalytically reacting carbon monoxide with a nitrous acid ester in gas phase in the presence of a solid catalyst comprising a catalytic solid material carried on a solid carrier and comprising:(1) a first component consisting of a platinum group metal or a compound thereof,(2) a second component consisting of a compound of Fe, Cu, Bi, Co, Ni or Sn,(3) a third component consisting of a compound of V, Mo or W, and(4) a fourth component consisting of a halides, for example, fluorides or chlorides, organic acid salts, for example, formates or acetates, or phosphates of an alkali or alkaline earth metal.