A monitoring system according to the present invention has a plurality of cameras respectively monitoring a monitor area and having a changeable imaging magnification, monitoring section detecting an object to be monitored in the monitor area, and control section selecting at least one camera capable of obtaining an enlarged image to contribute to identification of the object to be monitored as camera for enlargement from the plural cameras when the object to be monitored is detected and selecting at least one camera other than the camera for enlargement as camera for wide area from the plural monitoring camera. The camera for wide area is set to a first imaging magnification to obtain a wide area image of the monitor area and the camera for enlargement is set to a second imaging magnification larger than the first imaging magnification to obtain an enlarged image of the detected object to be monitored.