An atmosphere of a carbon source comprising an oxygenic compound is brought into contact with a catalyst with heating to yield single-walled carbon nanotubes. The carbon source comprising an oxygenic compound preferably is an alcohol and/or ether. The catalyst preferably is a metal. The heating temperature is preferably 500 to 1,500° C. The single-walled carbon nanotubes thus obtained contain no foreign substances and have satisfactory quality with few defects.