PURPOSE: To provide the titled apparatus which obviates the solidification of a molten metal to an inert gas blowing part consisting of a heater part and a body having pores of a specific inside surface area by providing said blowing member.

CONSTITUTION: An upper space 6 is formed by hermetic sealing with a bath vessel 3 for a molten metal 4 supplied with fused glass 1 adjusted in flow rate by a tuyere 2 and upper structures 7, 8. The inert gas blowing member 9 consisting of the header 11 connected with a piping 12 for an inert gas and the rectangular parallelpiped body 10 provided with the plural pores 14 having a ratio of 25W100cm2 for each 1Nm3/hr of the inerg gas to be blown is mounted to the side wall of the inside structure 7. The fall of the solidified metallic melt onto a glass ribbon and the generation of defects in the product are thereby prevented.