An intruding object monitoring apparatus, comprising: a camera having a zoom lens; an image processing unit (2106, 2107, 2108, 2109) for detecting an intruding object from image signals supplied from said camera; a pan/tilt head of said camera; a pan/tilt controller; a zoom controller; a communication unit (2105, 2117) for communication with at least another intruding object monitoring apparatus; a display for displaying an intruding object monitoring result; and a control unit (2108, 2109) for controlling to switch among a plurality of monitoring modes of the intruding object monitoring apparatus and said another intruding object monitoring apparatus; characterized in that wherein said monitoring modes include a normal mode (3001, 3101) for monitoring a predetermined monitoring area and a following mode (3002, 3103) to perform a following of an intruding object; wherein if said image processing unit detects an intruding object or said intruding object monitoring apparatus receives a following take-over request from an adjacent other intruding object monitoring apparatus when the monitoring mode of the intruding object monitoring apparatus is the normal mode (3001, 3101), the monitoring mode of the intruding object monitoring is switched to the following mode (2304, 2309, 3105) to perform a following of the request intruding object; wherein when the intruding object under a following by the intruding object monitoring apparatus enters a blind area of said camera, a following take-over request is transmitted to another intruding object monitoring apparatus having the monitor area including said blind area and the monitoring mode of the intruding object monitoring is switched to the normal mode. a camera having a zoom lens; an image processing unit (2106, 2107, 2108, 2109) for detecting an intruding object from image signals supplied from said camera; a pan/tilt head of said camera; a pan/tilt controller; a zoom controller; a communication unit (2105, 2117) for communication with at least another intruding object monitoring apparatus; a display for displaying an intruding object monitoring result; and a control unit (2108, 2109) for controlling to switch among a plurality of monitoring modes of the intruding object monitoring apparatus and said another intruding object monitoring apparatus; characterized in that wherein said monitoring modes include a normal mode (3001, 3101) for monitoring a predetermined monitoring area and a following mode (3002, 3103) to perform a following of an intruding object; wherein if said image processing unit detects an intruding object or said intruding object monitoring apparatus receives a following take-over request from an adjacent other intruding object monitoring apparatus when the monitoring mode of the intruding object monitoring apparatus is the normal mode (3001, 3101), the monitoring mode of the intruding object monitoring is switched to the following mode (2304, 2309, 3105) to perform a following of the request intruding object; wherein when the intruding object under a following by the intruding object monitoring apparatus enters a blind area of said camera, a following take-over request is transmitted to another intruding object monitoring apparatus having the monitor area including said blind area and the monitoring mode of the intruding object monitoring is switched to the normal mode.