1. An intruding object monitoring method for use in an intruding object monitoring system having a first intruding object monitoring apparatus for inputting images of a monitor area and at least one second intruding object monitoring apparatus for performing a following of an intruding object, the method comprising the steps of: acquiring first information of an object intruding into said monitor area with said first intruding object monitoring apparatus; transmitting said first information from said first intruding object monitoring apparatus to a second intruding object monitoring apparatus; capturing said intruding object with said second intruding object monitoring apparatus in accordance with said first information from said first intruding object monitoring apparatus; acquiring second information of said captured intruding object with said second intruding object monitoring apparatus; and following said captured intruding object with said second intruding object monitoring apparatus by controlling at least a camera of said second intruding object monitoring apparatus without control of said first intruding object monitoring apparatus.