A heat generator using a Carbon Nano Tube (CNT) composite material includes: an outer electrode part; an inner electrode part which faces the outer electrode part and is spaced apart from the outer electrode part at a predetermined distance; a connection part which connects the outer electrode part with the inner electrode part; and a bracket part which is disposed in the outer electrode part and the inner electrode part including the connection part to shield the outer electrode part, the inner electrode part and the connection part from each other. A surface of the connection part does not face directly the outer electrode part and the inner electrode part. The outer electrode part and the inner electrode part include electrodes having polarities different from each other.