We build an agent-based evacuation simulation model to measure the roles and effects of station staffs when passengers face emergency situations in an underground station. For this purpose, first we take up an actual station as a simulation space and classify passengers into three patterns, emergency escape pattern, return back pattern, and follower pattern. Then we implement computer simulations with or without station guidance in case of exit damage or fire. Our computational results confirm that sheltering at the nearest exit is not always a suitable decision-making for passengers and that the guidance of station staffs decreases the number of victims in spite that the total evacuation time increases.