PURPOSE: To obtain a linear member having the same cross-sectional configuration as a sleeve, by embedding a molybdenum sleeve having a specific cross-sectional configuration in synthetic resin block means, removing the sleeve to leave a groove having the same cross-sectional configuration as the sleeve in the block means, and passing a stock in said groove.

CONSTITUTION: A molybdenum sleeve 13 is prepared which has a cross-sectional configuration defined by a curved passage extending between cross-sectional ends, and after said sleeve 13 is embedded in the synthetic resin block, only said molybdenum sleeve is removed to leave a groove in said synthetic resin blocks, which groove is defined by the configuration and thickness of said curved passage. A stock is molded through said groove to obtain the linear member having the same cross section as the curved configuration.