The present invention relates to a reduction device using liquid metal, which can both improve the oxidation reaction of a reducing agent for reducing a material to be reduced using liquid metal and effectively control the same. The reduction device according to the present invention is characterized by comprising: a storage unit, liquid metal being supplied and stored therein; a reducing agent positioned in the storage unit; a reduction unit positioned on one side of the storage unit, a material to be reduced being contained in the reduction unit, and the reduction unit being able to exchange a fluid with the storage unit; and a liquid metal keeping unit. According to the present invention, a reducing agent, which has strong reducing capability, is sublimated using liquid metal, thereby further improving the reduction capability, and the same is controlled precisely, thereby removing restrictions on use resulting from the explosive reaction of the reducing agent, and guaranteeing efficient operation.