PURPOSE: A radiant tube is provided to have an extended service life by preventing damage to a straight pipe part and a bent part and to reduce energy and operation costs by increasing radiating efficiency. CONSTITUTION: A radiant tube comprises straight pipe parts(10) and bent pipe parts(20). One or more reinforcing units(30) are installed in the straight pipe parts and the bent pipe parts. Cylindrical support bars(21) are coupled to the bent pipe parts of the radiant tube. One surface of the support bars is opened.
