Disclosed are an unmanned monitoring system and a monitoring method for performing 360° unmanned monitoring work in equipment having a low storage capacity, such as a robot, by using one omni-directional camera. When an image is input through the omni-directional camera, a movement of an object is detected from the image. Then, the movement region is sampled by tracing the object and the image for the movement region is rotated into a frontal image while compensating for inclination of the image in order to allow a user to easily view the image. Thus, the frontal image is transmitted to a mobile communication terminal of a user, such as a mobile phone or a PDA.