A method comprises continuously supplying an alcohol to a pressurized reaction system, pressurizing carbon monoxide with a compressor 8 attached to a first feed line 22, for continuously supplying carbon monoxide to the reaction system via a second feed line 23 with a reference flow rate F, and converging excess carbon monoxide in the reaction system in the first feed line via a branched circulation line 24 for allowing to react alcohol with carbon monoxide. The reference flow rate F in the second feed line 23 is a total rate of a reference consumption flow rate Fcs in the reaction and a flow rate F1 in excess rate over a fluctuation consumption flow rate ΔFcv in the reaction system (F=Fcs+F1, F1>ΔFcv). According to the pressure fluctuation of the gaseous phase in the reaction system, the flow rate in the circulation line 24 is controlled to a flow rate Fr=F1−ΔFcv and the feed flow rate in the first feed line 22 is controlled to a flow rate Fsu=Fcs+ΔFcv, for compensating a consumption rate variation in the reaction system with the feed flow rate of carbon monoxide. This ensures discharge inhibition of the gaseous reactant in a liquid phase pressurized reaction system (such as carbonylation reaction system) and effective utilization of the reactant for the reaction.