Provided is a production method that forms a group comprising multiple carbon nanotubes having a high vertical orientation, which are oriented in a vertical direction with respect to the surface of a base, without using terpineol, which is a thickening agent. A catalyst solution is prepared that has a predetermined concentration (0.2 M to 0.8 M) of a transition metal salt dissolved therein, and that does not contain terpineol. Catalyst particles are caused to be present in the surface of the base by bringing the catalyst solution and the surface of the base into contact. A carbon nanotube forming gas is brought into contact with the surface of the base in a carbon nanotube forming temperature region, and the group comprising multiple carbon nanotubes, which are oriented in the vertical direction with respect to the surface of the base, are grown on the surface of the base.