NOVELTY - The methane synthesis reactor comprises a catalysis part (210), where synthetic methane gas is ejected into the catalysis part, a reactor (200) equipped in an inner duct, a vent (300) for ejecting the methane gas and comprising an inlet port (100), a methane synthetic liquor catalyst main part (211) in which the injected synthetic gas reacts first inside the reactor, methane synthesis anticatalyst parts in which the unreacted synthetic gas passing via the catalyst main part reacts secondly, and a heat exchanger provided for heat recovery from the catalyst main part and the anticatalyst parts.    USE - Used as a methane synthesis reactor.    ADVANTAGE - The methane synthesis reactor prevents leakage of explosive gas such as carbon monoxide and hydrogen generated from an exterior pump and improves methane coupling efficiency, and is energy efficient.    DETAILED DESCRIPTION - The methane synthesis reactor comprises a catalysis part (210), where synthetic methane gas is ejected into the catalysis part and the unreacted synthetic gas circulates in the methane synthesis reactor, a reactor (200) equipped in an inner duct, a vent (300) for ejecting the methane gas and comprising an inlet port (100), a methane synthetic liquor catalyst main part (211) in which the injected synthetic gas reacts first inside the reactor, methane synthesis anticatalyst parts in which the unreacted synthetic gas passing through the catalyst main part reacts secondly, and a heat exchanger provided for heat recovery from the catalyst main part and the anticatalyst parts. The reactor is equipped to the inner duct and a path for being transferred to the catalyst main part. The vent is connected to the reactor. A driving apparatus is equipped with the inlet port and fixed to a rotary shaft. The driving apparatus is driven with a pressure of the injected synthetic gas through the inlet port. The heat exchanger equipped within the catalysis part is filled with water at a room temperature. The synthesized methane gas at high temperature is contacted with the water in the heat exchanger at the room temperature, and the steam is generated by the contact so as to lower the temperature within the catalysis part. A circulator is formed at the vent, and transfers the synthetic methane gas and the unreacted synthetic gas to the inner duct within the reactor. An INDEPENDENT CLAIM is included for a methane manufacturing method.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a methane synthesis reactor.    Inlet port (100)    Reactor (200)    Catalysis part (210)    Methane synthetic liquor catalyst main part (211)    Vent. (300)