A refractory block which has a construction wherein the outer peripheral surface of a unitary assembly of plate bricks and an immersion nozzle is directly encompassed by a unitary metal case. It is also possible to employ a construction wherein plate bricks stored in a metal case are bonded to the dowel portions of the immersion nozzle stored in a separate cylindrical metal case through mortar and the metal cases are welded integrally to each other, a construction wherein a unitary refractory block of the plate bricks and the immersion nozzle is encompassed by a unitary metal case, or a construction wherein the unitary refractory block is fitted to a unitary metal case through an amorphous refractory. The unitary refractory block may be a combination of different kinds of refractories, and it is further possible to employ a construction wherein the plate bricks and the immersion nozzle are fitted into a unitary metal case with porous bricks sandwiched between the plate bricks and the immersion nozzle, and feed/discharge pipes are so disposed in the porous bricks as to penetrate through the metal case. <IMAGE>
