In order to fill a casting mould with a molten metal, the latter is caused to flow into through an annular chamber into the shaped cavity of a casting mould, such annular chamber discharging over the entire external periphery of the shaped cavity into the latter. The inflow of molten metal into the annular chamber is interrupted by means of a piston, which, being borne inside the annular chamber, is capable of sliding therein. The molten metal can be caused to flow across a large flow cross-section, which shortens the filling time even with reduced flow velocity.