PROBLEM TO BE SOLVED: To provide an apparatus for solidifying steelmaking dust which can produce a solidified article having high strength while minimizing an amount of an additive to be added to the raw dust, and enhance a thermal efficiency of a furnace when the solidified article has been recharged into the furnace. SOLUTION: The apparatus 4 for solidifying the steelmaking dust is directed at preparing a granulated raw material 11p mainly into grains by granulating a mixed powder of the steelmaking dust and a powder mainly containing carbon, and compressing the raw material 11p into the solidified article 41; and comprises a water addition means 10 and a solidification mechanism 12. The steelmaking dust comprises iron and the oxide as a main component, which are produced in a steelmaking process. The water addition means 10 impregnates water into the raw material 11p mainly formed of a granulated body obtained by a granulating device 5. The solidification mechanism 12 compresses the raw material 11p mainly formed of the granulated body to which water has been added by the water addition means 10, in a molding die 30 to form the solidified article 41. COPYRIGHT: (C)2007,JPO&INPIT