Abstract: A sleeve assembled in a casting apparatus through which a molten metal is fed into a die cavity, characterized in that at least part of said sleeve on which the molten metal impinges or flows fast under high pressure is made of cemented carbide consisting essentially of a hardening phase of WC, part of which may be substituted by TaC, NbC, TiC, etc., and 10-20 weight % based on the cemented carbide of a binder phase comprising Co, Ni, Cr, and optionally Mo, a weight ratio of Cr+Mo to the binder phase being 0.1-0.2 and a weight ratio of Mo to Cr being up to 3. This sleeve, when assembled in a die-casting apparatus or a low-pressure casting apparatus, enjoys an extremely long life because of its high resistance to oxidation and washing.