Abstract: A device for sensing the free surface level of melt in a continuous casting mold having an electromagnetic stirrer consisting of stirrer coils and magnetic poles therefor disposed around the circumference of the mold. The device is characterized in that at least one elongated radiation source extending in the direction of casting is arranged on one side of the mold, and that a detector for the radiation with a small extension in the casting direction is arranged on substantially the diametrically opposite side of the mold but at a height different from that of the radiation source. In the radiation path from the source to the detector an oblong slot is provided for the passage of the radiation through the pole of a stirrer coil.