To provide a method of producing hydrogen and carbon monoxide under a mild reaction condition at high yield and an apparatus for producing the same.

The method of producing hydrogen and carbon monoxide from dimethyl ether (DME) used as a raw material uses a reactor having a steam reforming catalyst packed in the upstream side, a carbon dioxide gas reforming catalyst packed in the downstream side and a hydrogen separation membrane attached adjacent to the hydrogen reforming catalyst and the carbon monoxide reforming catalyst to separate produced hydrogen and comprises a step for injecting DME and steam into the reactor, a step for producing hydrogen and carbon dioxide gas from the injected DME and steam with the steam reforming catalyst, a step for separating only hydrogen from produced hydrogen and carbon dioxide gas by the hydrogen separation membrane, a step for producing hydrogen and carbon monoxide from carbon dioxide gas produced simultaneously with hydrogen and DME remaining in the reactor with the carbon dioxide gas reforming catalyst, and a step for separating only hydrogen from produced hydrogen and carbon monoxide by the hydrogen separation membrane.