Adsorption and desorption characteristics of methyl iodide at high temperature conditions up to 250\'C by TEDA-impregnated activated carbon, Which is used for radioiodine retention in nuclear facility, was experimentally evaluated. In the range of temperature from 30\'C to 250\'C, the adsorption capacity of base activatedcarbon decreased sharply with increasing temper-ature but that of TEDA-impregnated activated carbon showed higher value even at high temper-ature ranges.