In this study, we proposed concepts of a vertiport airspace design that must precede for the practical operation of urban air mobility, an emerging new urban mobility solution. We developed algorithms to find the optimal radius of airspace for each concept and, through simulations, derived comparisons among them. We also introduced the concept of a vertiport terminal control area where an personal air vehicle (PAV) approach control is performed, which consists of holding points and holding circles. Two strategies of PAV movement into the inner holding circles were proposed: the sequence-based approach (SBA) and the branch-queuing approach (BQA). The efficiency of these strategies was compared through a simulation, which demonstrated that the SBA is suitable for a space-constrained vertiport design and the BQA for a safer airspace design.