A device (20) for manufacturing a carbon nanotube array (10) includes a reaction chamber (220), a gas introducing tube (228), and a quartz boat (240). The reaction chamber includes a first gas inlet (222), a second gas inlet (224), and a gas outlet (226). The first gas inlet is configured for introducing a reaction gas, and the second gas inlet is configured for introducing a disturbance gas. The quartz boat is disposed in the reaction chamber. The quartz boat is used to carry a substrate (12) from/upon which the carbon nanotube array grows. The gas introducing tube is connected to the second gas inlet and to the quartz boat. The gas introducing tube is used to transport the disturbance gas introduced from the second gas inlet to the quartz boat to disturb/interrupt nanotube growth.