A low-pressure casting apparatus includes a casting mold having upper and lower molds, a lower mold platen to which the lower mold is fixed, a molten metal holding furnace which holds molten metal to be supplied to a cavity in the casting mold and is disposed in a position offset from the casting mold, a cutaway portion which is formed in the lower mold platen to open toward the furnace and a molten metal supply pipe which extends obliquely upward through the cutaway portion from the furnace to the lower mold to connect the furnace to the cavity. The molten metal supply pipe is arranged to connect the casting mold and the furnace with the molten metal supply pipe supported on a support table and the support table is provided with a pressing mechanism which presses the pipe against the furnace to connect the furnace-side end of the pipe to the furnace.