NOVELTY - A spherical storage tank (1) bears preset pressure. The raw material water circulation duct (5) is provided with a coil evaporator (4) to which coolant is supplied from the refrigerator (6). The water pipe (11) and pump (13) extracts water from the bottom of the tank and supplies to the bottom of duct. The gas piping (10) and injection nozzle (7) injects natural gas into water at the bottom of the tank.    USE - To manufacture methane hydrate which is produced and stored within the same container capable of bearing predetermined pressure.    ADVANTAGE - The raw material water and natural gas contact efficiently by injecting natural gas into water at the bottom of the container. Manufactured hydrate is stably stored in liquid phase at the upper portion of the container. The unconverted gas is reused which enables effective usage of raw material gas and increases the utilization factor of the natural gas. The temperature of the raw material water circulating in the tank is controlled and the hydrate is efficiently manufactured by preventing adherence of hydrate to the surface of the coil evaporator. The product gas is regenerated by fusing and the supply of gas is reliable.    DETAILED DESCRIPTION - Methane hydrate manufacturing apparatus has circulation piping (9) which connects the upper portion of the tank (1) and the raw material gas piping (10). Heat release load piping (18) extracts the liquid from the bottom of the tank and supplies to the upper portion of the tank through a load heat exchanger (15). The resurgent gas is supplied to the piping (17) connected to the upper portion of the container. An INDEPENDENT CLAIM is also included for methane hydrate manufacturing method which involves injecting natural gas at the bottom of the pressure container into water at 0-6.5degreesC and 26-60 Kg/cm2 pressure. The manufactured methane hydrate is stored in liquid phase at the upper portion of the spherical container. The temperature of the water circulating in the tank is controlled by the coil evaporator. The unreacted natural gas in the upper portion of the tank is circulated at the bottom of the tank and reused as raw material. The resurgent gas is generated by fusion of methane hydrate using fusion sprayer (14).    DESCRIPTION OF DRAWING(S) - The figure shows the methane hydrate manufacturing apparatus.    Spherical storage tank (1)    Coil evaporator (4)    Water circulation duct (5)    Refrigerator (6)    Injection nozzle (7)    Circulation piping (9)    Gas pipings (10,17)    Water pipe (11)    Pump (13)    Heat exchanger (15)    Load piping (18)