An apparatus for producing a superconducting oxide film with stable properties by metal organic chemical vapor deposition, suitable for mass production, is provided with a gas analyzer comprising a differential pressure meter 38 between a raw material gas collector tube 35 provided in a transfer line 8 for leading a raw material gas to a film forming chamber 10 and a bypass line 37, a dilution gas line 49 interlocked with the differential pressure meter 38 and for leading a dilution gas to the raw material gas collector tube 35, a gas separation column 42 branched from the bypass line, a gas detector 31 connected to the gas separation column 42, flow rate controllers 50 for carrier gases 43 and 45 and a thermostat 13 for heating all the lines. Amounts of raw materials gases can be readily measured and controlled and thus superconducting oxide films of stable properties in a constant metal composition ratio can be continuously produced, and thus the present apparatus is suitable for mass production of tape form, superconducting materials.