The objective of this study is to evaluate thermal performance of suggested double skin fa?ade by comparing with conventional fa?ade. The evaluation was performed by experiments of conventional fa?ade and double skin fa?ade through the extreme conditions. For evaluation of thermal performance, peak cooling load and peak heating load is measured. For this measurement, ceiling, floor, all the walls are adiabatic condition except for the location of building fa?ade. And to keep the constant indoor temperature, air is supplied through AHU. In the process of evaluation on thermal performance, outdoor temperatures is applied maximum temperature of daytime in summer condition and minimum temperature of nighttime in winter condition using Seoul weather data. Indoor temperature is used Recommended temperature of energy conservation code in Korea. And according to the survey, Maximum vertical solar radiation during the daytime is applied. As a results, Double skin fa?ade could reduce peak cooling load by 60% or more than conventional fa?ade during summer peak condition. And the operation of double skin fa?ade during winter peak condition also could reduce peak heating load by 30% or more than operating conventional fa?ade.