PURPOSE: To obtain a titled vessel which is capable of executing desiliconizing and dephosphorization without executing the sediment discharge in 2 chambers, by constituting it of 2 chambers divided by a partition wall provided with a communicating port on its lower part, and incline-moving it so that a molten metal stored in the vessel can be moved between the 2 chambers.

CONSTITUTION: A vessel body 1 which has been provided with a communicating port on its lower part and has been divided into 2 chambers by a partition wall 2 is incline- moved by an angle α by making a supporting point P an axis, a molten metal 9 is injected into the first chamber 31 of the lower side to the extent that it does not reach the communicating port 4, a desiliconizing flux 12 is blown into the molten metal 9 from a lance 11, and desiliconizing treatment is executed. Subsequently, the vessel body 1 is incline-turned by an angle β, a desiliconized slag generated by a desiliconizing reaction is checked by the partition wall 2, only the molten metal 9 of the whole quantity is moved to the second chamber 32 which has become the lower side, a dephosphorizing flux 15 is blown in from a lance 14, and dephosphorizing treatment is executed. After the treatment has ended, an opening and closing means 5 of a sliding gate, etc. is operated, a generated dephosphorized slag 16 is left in the second chamber 32, and only the molten metal 9 is taken out from a discharge port 6.