Intruding object monitoring method and intruding object monitoring system

An intruding object monitoring method using an intruding object monitoring system having a first intruding object monitoring apparatus (101, 502) for monitoring a monitor area by inputting images of the area and at least one second intruding object monitoring apparatus (102) for performing a following of an intruding object. By this method, first intruding object monitoring apparatus acquires detection information of an object intruding into the monitor area (202), the second intruding object monitoring apparatus captures the intruding object in accordance with the detection information supplied from the first intruding object monitoring apparatus. After the intruding object is captured, the second intruding object monitoring apparatus performs the following of the captured intruding object independently of the first intruding object monitoring apparatus (304-310).