To provide a method and device for transferring NGH under a high pressure to under a normal pressure.

In the method for transferring natural gas hydrate (hereinafter referred to as NGH) manufactured by reacting water and natural gas under the high pressure to under the normal pressure by a screw type transfer device, the screw type transfer device 1 comprises a barrel 10 including a supply port 12 of the NGH arranged on one end, and a screw shaft 11 supported in the barrel 10, and is provided with a closed wall body 30 with a discharge port 13 opened on an end or a part continuing to the end of the barrel 10, and further is provided with a pressurizing chamber 2 of a predetermined capacity formed between a tip end part of the screw shaft 11 and the closed wall body 30. The method for transferring the NGH emits the NGH to a low pressure band side while maintaining a high pressure on a supply side during transferring via the screw type transfer device 1 by temporarily accumulating the NGH in the pressurizing chamber 2 by opening and closing a valve device 16.