The authors have conducted experiments to measure personal space between a human and a humanoid robot using both a real and a VR (virtual reality) humanoid robot in order to evaluate the comfortable distance between them. The reason for using both a real and VR robot is to verify the effectiveness of VR. Using a VR robot, we can conduct experiments cheaply and safely because the robot has an unsubstantial body. As a result of our experiment, we have found that the personal space between a human and a humanoid robot matches the personal distance between two persons who are in a relationship of friendship. Also, no differences were seen in the shape of the personal space for a real robot and a VR robot significantly.