1. An object detection system that uses a first and a second electromagnetic wave detection means having different sensitive wavelengths and executes coordinated processing on detected information to detect an object, wherein the first electromagnetic wave detection means image-picks up an object being monitored as a two-dimensional image; wherein, in the two-dimensional image picked up by the first electromagnetic wave detection means, an area range is determined based on the detected information from the second electromagnetic detection means and, in that area range, image processing is performed to detect the object.