FIELD: furnaces and methods of spinning of optical fibers. SUBSTANCE: furnace has inlet and outlet openings. Provision is made for heating elements for heating optical fiber intermediate products supplied inside through inlet opening to provide for stretching of optical fiber without coating from outlet opening. Flowing inert gas is provided from furnace inside through inlet opening. Internal surface of inlet bushing having inlet hole includes projections and depressions which increase its resistance to flow of outgoing inert gas. The method consists in that intermediate product is connected with auxiliary quartz rod of small diameter and auxiliary quartz tube is fitted on auxiliary quartz rod so that quartz tube thrusts the intermediate product, and intermediate product, quartz rod and tube are installed into chuck of the device for spinning of optical fibers. EFFECT: minimum pressure variation in furnace and variation of inert gas flow velocity in furnace. 20 cl, 7 dwg
