To provide a low speed and high pressure casting apparatus by which the fixed quantity of molten metal can accurately be supplied into a cavity of a die for each casting without depending on fixed quantity supply performance with a molten metal supply device (molten metal supply pot).

A gas flowmeter 7 is connected to a gas exhaust vent 6 formed of the die 1, and an exhaust gas amount pushed out to the outside through the gas exhaust vent 6 from the cavity of the die as the molten metal is supplied and filled up into the cavity 11 of the die from a molten metal flow-in hole 4 is measured by the gas flowmeter 7. When the exhaust gas amount becomes a set value, a signal for completing the supply of the molten metal is outputted and simultaneously, a signal for starting pressurizing movement is outputted to a pressurizing element.