The invention shows a production apparatus for producing carbon nanotubes by the gas-phase catalysis process, comprising: a first chamber having a growth region that is a region in which carbon nanotubes are formed; a first temperature adjustment device capable of adjusting a temperature of the growth region in the first chamber; a pressure adjustment device capable of adjusting a pressure in the first chamber; a first feed device capable of feeding a carbon source to the growth region in the first chamber; a second temperature adjustment device capable of adjusting a temperature of a solid-phase iron family element-containing material disposed in the production apparatus; and a second feed device capable of feeding a gas-phase halogen-containing substance into the production apparatus so that the iron family element-containing material of which the temperature is adjusted to a predetermined temperature by the second temperature adjustment device can react with the halogen-containing substance.