PURPOSE: To efficiently adsorb the inclusion with the simple operation by dipping the refractory blocks having a plurality of projections to absorb the inclusion in the molten steel in the tundish or floating the refractory blocks on the molten steel in the tundish.

CONSTITUTION: The refractory block is the refractory block 20 of the tetrapot shape having a plurality of projections, providing the stability and the straightening effect when the molten steel is filled in the tundish 2. In addition, the material is of Ca base which is excellent in the adsorption of the inclusion. From the viewpoint of more effective adsorption of the inclusion, the filling range is the molten steel falling range 9 to supply the molten steel from the ladle 1 to the tundish 2, and the floating range is the range 10 to float and separate the inclusion which is the floating part of the inclusion and the molten steel supplying range 11. In order to prevent the out-flow of the refractory blocks in the transverse direction when the blocks are packed in the vertical direction, only the upper part of the upper gate 5 is made the lattice gate 22 or the communicating hole 23 is provided to prevent the out-flow in the transverse direction.