To unload and transport low-temperature methane gas hydrate pellets in a dry condition from a carrying vessel and storage tank without using liquid refrigerant, such as antifreeze solution and cryogenic liquefied gas.

In this device for successively sucking the methane gas hydrate pellets and unloading them, the methane gas hydrate pellets are sucked by exhausting methane gas from a suction pipe. After the methane gas hydrate pellets accelerated in a nozzle portion in front of an exhaust port pass through an openable/closable diaphragm, high-pressure methane gas is blown out to transport the methane gas hydrate pellets. Successive suction is permitted, due to functions of the nozzle portion placed in the proximity of the exhaust port of the suction pipe, the openable/closable diaphragm and a methane gas blowout nozzle for transportation.