Nowadays, the needs of various evacuation strategies and evacuation methods have been tremendously increasing because the heights of buildings become higher. Especially, the simultaneous evacuation strategy using egress elevator, which has been prohibited in evacuation procedure traditionally, is gradually treated the essential evacuation method in the post-9/11 environment such as in fire protection engineering-developed countries. However; existing evacuation factors which were deprived from crowd movements of stairwell systems cannot be only inputted in elevator evacuation systems but also the maximum flow-density cannot be inputted neither because the stairwell evacuation systems and elevator evacuation systems are definitely composed in different mechanism. Therefore; this study executed the trial experiments for a measurement of maximum flow-density when the evacuees board or depart through the elevator. Measured maximum flow-density from the experiment is also used in the developed model of elevator evacuation time calculator which can estimate the overall evacuation time from boarding the elevator to departing and reaching to the safe place on the ground floor and finally will be applied in the high-rise building evacuation simulator.