in a vacuum - die casting machine comprising a casting mold having stationary and movable mold halves defining therebetween a mold cavity , a casting chamber which is in communication with the mold cavity and includes a piston and an evacuation arrangement connectable to the casting chamber for drawing melt from a melt storage into the casting chamber , a control arrangement is provided for controlling the mold cavity pressure depending on the pressure difference between the mold cavity and a cavity pressure and a counter pressure of the metal melt .