A reduction device using a liquid metal, which can improve the oxidation reaction of a reducing agent for reducing a material to be reduced using a liquid metal, while simultaneously effectively controlling the same. The reduction device according to the present invention comprises: a storage unit in which the liquid metal is supplied and stored; a reducing agent positioned in the storage unit; a reduction unit positioned on a side of the storage unit, which receives a material to be reduced and enables fluid communication with the storage unit; and a liquid metal storage unit. According to the present invention, a reducing agent, which has strong reducing ability, is sublimated using a liquid metal, thereby further improving the reduction capability, and the same is also controlled precisely, thereby removing restrictions on use resulting from the explosive reaction of the reducing agent and guaranteeing efficient operation.