A device is disclosed for preventing the evaporation of a liquefied gas stored in an impervious and thermally insulating tank built into a bearing structure of a ship or located in a set of floating or land-side storage tanks. The device passes a fluid refrigerant through the mass of liquefied gas to cool the mass to a temperature slightly below its reference storage temperature. By so doing, the refrigerant compensates for the heating of the mass, due to thermal leaks within the insulating tank, during the transport or storage of the liquefied gas.