Abstract: Provided is a laser amplification medium cooling device capable of effectively dissipating heat generated in a laser amplification medium. The laser amplification medium cooling device includes a cooling module configured to cool an amplification medium for amplifying a laser, wherein the cooling module includes a cooling chamber having a flow path accommodating the amplification medium formed therein and a refrigerant flowing along the flow path to cool the amplification medium, wherein the refrigerant is a metallic fluid that maintains a liquid state at room temperature.