Abstract: Provided is an apparatus for controlling temperature of a black body. The apparatus includes a black body emitting radiant energy of infrared rays; a first Peltier element adjacent to the black body, the first Peltier element having a 1a surface and a 1b surface that selectively emit or absorb heat; a copper plate adjacent to the 1b surface; a second Peltier element adjacent to the 2b surface, the second Peltier element having a 2a surface and a 2b surface that selectively emit or absorb heat; a heat transfer member comprising a bent surface adjacent to the 2a surface, and an arm extending toward both ends of the black body to be adjacent to the both ends of the black body and a control unit controlling the 2a surface to emit heat when the 1a surface emits heat, and the 2a surface to absorb heat when the 1a surface absorbs heat.