The present invention relates to a method for producing carbon nanotubes, comprising a synthesis step of synthesizing carbon nanotubes on a support on which a catalyst is supported by flowing a source gas consisting of acetylene, carbon dioxide, and an inert gas over the support, wherein in the source gas, a partial pressure of the acetylene is 1.33×101 to 1.33×104 Pa, a partial pressure of the carbon dioxide is 1.33×101 to 1.33×104 Pa, and a partial pressure ratio of the acetylene to the carbon dioxide (acetylene/carbon dioxide) is in the range of 0.1 to 10.