To enable long-term continuous operation by preventing blocking of a reaction pipe line disposed in a multi-pipe or double-walled-pipe heat exchanger, provided is a device for producing gas hydrate including a multi-pipe or double-walled-pipe device 1 for generating gas hydrate having a reaction pipe line 2 for flowing raw material water w and raw material gas g and a coolant circulation region 3 for circulating a coolant c and thereby cooling the reaction pipe line 2, wherein a coil spring 4 extending in the longitudinal direction of the reaction pipe line 2 is provided in the reaction pipe line 2.