PURPOSE: To remove remaining nonmetallic inclusions in molten steel by adsorption and to form sound continuous casting slab, by arranging layer refractory having communicating holes at inner part with specified range of diameter and porosity on the whole face of tundish inner wall or the specified face thereof.

CONSTITUTION: On the whole face of the tundish 2 inner wall, brought into contact with the molten steel or on the face apart from a ladle nozzle 4 and near a submerged nozzle 5, the refractory plate 7 having the communicating holes at the inner part with 0.5W6mm average diameter of holes and 20W70% porosity, is arranged. The refractory 7 uses calcined plate, composing of such as SiO2, Al2O3, ZrO2, MgO, CaO, TiO2, graphite, etc. In this way, the remaining suspended nonmetallic inclusions in the flowing molten steel poured into the tundish 2 are removed by adsorption and quality of the continuous casting slab poured into a mold 3 through the submerged nozzle 5 is improved. When this refractory plate 7 reduces its adsorptivity, it is exchanged at suitable timing.