The effort of energy saving in building has kept going. So the envelope of building has more improved about thermal performance for energy saving. The window at envelope of buildings has low thermal performance than thermal insulation and external wall. Therefore manufacturer has improved the thermal performance of windows by various method. In case of the improvement about the window performance, recently the vacuum glazing has received attention. Also the vacuum glazing window was researched by many researcher for the excellent thermal performance(like a low U-value). Commonly the vacuum glazing has low U-value and thin thickness than existing functional double glazing. But the frame of window has low thermal performance than vacuum glazing. For the optimum vacuum glazing window, the frame and glazing has suitable combination. In this paper, the authors confirmed the variation of thermal performance about vacuum glazing edge and frame through different of glazing pocket detail. In case of deep about glazing depth, the U-value of vacuum glazing edge(Uedge) was decreased maximum 0.95 W/m²·K and the U-value of frame(Uf) was decreased maximum 0.16 W/m²·K. Also the case of the increase glazing thickness, the U-value of vacuum glazing edge(Uedge) was decreased maximum 0.25 W/m²·K and the U-value of frame(Uf) was decreased maximum 0.08 W/m²·K.