PURPOSE: To facilitate fitting work at the time of fitting a brake ring to a horizontal mold for horizontally continuous casting and to prevent the development of cold shut crack in a cast billet.

CONSTITUTION: In a space ring 12 arranged between the horizontal mold 10 and the brake ring 11, both end faces 12b, 12c thereof are formed as inclined shape so as to closely contact with inclined end faces of the mold 10 and the spacer ring 11, respectively, and difference between the min. inner diameter contacting with the brake rind 11 and the max. inner diameter contacting with the mold 10, is in the range of 4-20mm, and length of inner face in the spacer ring 11 is length of drawing pitch for cast billet drawn from the mold 10 or less.