Provided is a low-pressure casting apparatus for stable casting without using feedback control even if a furnace body has a crack, and a low-pressure casting method using the same. A low-pressure casting apparatus fills a cavity with molten metal M through a guiding unit by introducing gas into a holding furnace for heating the molten metal M to apply pressure to a surface of the molten metal M. The holding furnace includes a casing, a furnace body accommodated in the casing, and a refractory layer disposed between the casing and the furnace body, the refractory layer having a pore structure. The low-pressure casting apparatus further includes a first gas supply unit for supplying to the furnace body the gas to apply pressure to the molten metal M and a second gas supply unit for supplying gas to the refractory layer.