There is provided a device for manufacturing carbon nanotube. The devices has a chamber support part for supporting a chamber which contains a plurality of microstructures, each of which is separated from each other by an interval; a gas providing part, connected to the chamber, for flowing at least one reactant gas, including raw material gas for manufacturing carbon nanotubes, through the chamber; a measurement part for measuring a change in physical properties of at least one of the plurality of microstructures by using detecting part; and a control part for controlling the gas providing part based on the measured change in physical properties.