To provide a mold apparatus, invented so that a strainer supplied from inclined upper part is reduced to project out a strainer holding chamber, related to the mold apparatus provided with the strainer holding chamber, in which a platy strainer for filtering slag in molten metal is supplied from the inclined upper part to a receiving inlet opened toward the upper part under state of opening the mold and the molten metal is flowed from the lower surface side by connecting the upper part with the runner forming space under state of closing the mold.

The strainer holding chamber 2 has a groove part 22 extended to the peripheral direction of the lower surface 21 in a portion at the reversed side at least to the supplying side of the strainer S on the outer periphery of the lower surface 21.