A metal surface treatment device, according to the present invention, is a metal surface treatment device which carries out surface treatment for a target metal heated at a temperature for which surface treatment is possible, the device comprising: a reaction chamber which has a shape corresponding to an outer shape of the target metal and is arranged within a certain interval from the outer side of the target metal, and which accommodates at least a part of the target metal; and a raw gas supply unit for supplying raw gas which is necessary for an autocatalytic reaction with the target metal accommodated within the reaction chamber. Furthermore, a metal surface treatment method using the same comprises the steps of: positioning a target metal within the reaction chamber, which has the shape corresponding to the outer form of the target metal and is arranged within a certain interval from the outer side of the target metal and which accommodates at least a part of the target metal; and forming a raw gas layer
