A method of manufacturing a honeycomb metal structure includes providing a substrate comprising iron (Fe) and a container containing water; coating at least a part of the substrate with a viscid material whose viscidity is increased by moisture; attaching metal powder onto the viscid material; adhering the metal powder to the substrate due to an increase in viscidity of the viscid material by evaporating a portion of the water in the container and supplying moisture to the viscid material; and generating an uneven structure made of the metal powder bonded to the substrate by performing a heat treatment on the substrate to which the metal powder is adhered. The heat treatment may include performing a first heat treatment on the substrate to generate an intermetallic layer at an interface between the substrate and the metal powder; and performing a second heat treatment to dissolve the intermetallic compound layer.