To provide a melting tank which is used in melting raw material by high frequency induction heating in a magnesium or magnesium alloy casting machine and restrains molten metal from adhering to the tank and has excellent durability.

The melting tank of this invention is composed of an AlN-BN sintered body. The AlN-BN sintered body can be used as material for the melting tank in high frequency induction heating, since it is non-magnetic material having excellent insulation properties. Further, the AlN-BN sintered body restrains molten magnesium from adhering whereby it is not easily eroded by molten magnesium, and is excellent in thermal shock resistance. Sialon can be substituted for the AlN-BN body.