To provide a rotary body for stirring molten metal which has low possibility of breakage of a shaft or a rotor and allows impurities in molten metal to be treated for a long time even in the case that not only the rotary body for stirring molten metal is rotated in one direction but also it is rapidly inverted from the left-handed rotation to the right-handed rotation or from the right-handed rotation to the left-handed rotation, in order to increase the removing efficiency of impurities in molten metal, and a degassing treatment apparatus provided therewith.

The rotary body 1 for stirring molten metal is constituted so that a rotor 5 stirring molten metal 2 is fitted to one edge part of a cylindrical shaft 4, and a connection tool 3 to be connected to a rotary driving mechanism 6 is fitted to the other edge part, wherein the surfaces of the shaft 4 and the rotor 5 are provided with rugged parts 11 with a height higher than the thermal expansion upon using of ceramics used for the shaft 4 or the rotor 5, and the shaft 4 and the rotor 5 are engaged and joined by the shrinkage of the ceramics upon firing in a form of combining the rugged parts 11.