Glass-melting device for producing glass fiber and method for producing glass fiber

A glass-melting device for producing glass fibers, comprising:

• a first glass-melting tank;
• a conduit extending downwardly from the first glass-melting tank;
• a first sucking device for exposing the first glass-melting tank to a reduced-pressure atmosphere;
• a second glass-melting tank provided on a lower portion of the conduit and exposed to an atmospheric-pressure atmosphere;
• and
• a bushing provided on a bottom portion of the second glass-melting tank and having a number of nozzles,
• a heat insulating material accommodated in a decompression housing, wherein the first glass-melting tank and the conduit are covered with the decompression housing in which a pressure is reduced by the first sucking device,
• a partition member for partitioning the heat insulating material in the decompression housing, and
• a heat insulating material insertion opening for inserting an elastic heat insulating material into the decompression housing, wherein the heat insulating material insertion opening is formed immediately under the partition member.