A bearing box for a rotating roller for supporting or transporting a high-temperature object. The bearing box includes a bearing and seal units disposed therein. A cooling jacket is disposed at an outer periphery of the bearing box so that the cooling jacket covers at least a portion of an axial region of the bearing and at least a portion of an axial region of the seal unit. The cooling jacket has a cooling water inlet and a cooling water outlet, and the bearing box is cooled by cooling water supplied to the cooling jacket through the cooling water inlet.