Far Infrared radiators should have functionality to convert thermal energy into an electromagnetic wave. In order to apply the Far Infrared to the substance, the absorption characteristics of the substance should be considered. In this paper, interrelation of emissivity with emission energy according to temperature in the range of [$2.5mu extrm{m}$] to 25[$mu extrm{m}$] after the transition element oxides (MnO2, Fe2O3, CuO, Co3O4) of first grade reagent were molded in press, then they were sintered in [$1050^{circ}C$], and they were used as samples.