PURPOSE: To effectively protect the parts exclusive of the surface to be treated by immersing an object to be treated exclusive of the surface to be treated into a protective material in a molten state and subjecting the surface to be treated to a surface treatment after curing of the protective material at the time of subjecting the surface to be treated, such as adhesive surface of the dentition orthodontic bracket, to the surface treatment.

CONSTITUTION: The layer of the thickness approximately equal to or slightly lower than the height of the object 30 to be treated when the surface 31 to be treated is faced upward is melted by heating at temp. of surface treatment with solid. The protective material 20 consisting of natural wax, synthetic wax, thermoplastic high polymer, etc., is put into a container 60 and is melted and cooled, by which a protective material layer 21 having a uniform thickness is formed. The object 30 to be treated is then placed on the protective material layer 21 by directing the surface 31 to be treated upward and the entire part is heated in this state to melt the protective material layer 21, by which the object 30 is sunk into the layer 21 and only the surface 31 to be treated is exposed on the layer 21. The surface 31 is thereafter subjected to the desired surface treatment, such as sandblasting treatment and a treatment by a corrosive material.