Provided are a cold heat recovery apparatus using an LNG fuel and a liquefied gas carrier, in which costs involved in the installation and operation of a reliquefying facility can be reduced by recovering and utilizing cold heat of the LNG fuel when boil-off gas of liquefied gas as a cargo is reliquefied, and energy saving and reduction of environmental pollutants can be achieved because additional energy is not consumed in a reliquefaction process. A cold heat recovery apparatus for processing boil-off gas generated in a liquefied gas tank by using cold heat of an LNG fuel includes cold heat usage means using cold heat of an LNG supplied from an LNG fuel tank storing an LNG as a fuel to an engine, so as to processing the boil-off gas generated in the liquefied gas tank.