A specific object such as a human body can be visualized in a wide range in a relation to its background night and day to definitely identify a location of the object in relation to the background as well in the infrared image captured by the infrared camera. The present invention provides an imaging device including a color camera unit for making color imaging with the imaging direction being sequentially adjusted for each of unit images forming together a panoramic image, an infrared camera for imaging by infrared radiation measurement with the imaging direction being sequentially adjusted for each of unit images forming together a panoramic infrared image, a server for storing/managing a panoramic color image produced by overlaying a plurality of unit images captured in colors by the color camera unit one on the other and a panoramic infrared image produced by overlaying a plurality of unit images captured by infrared radiation measurement by the infrared camera one on the other, an image synthesizer for overlaying, on an image of an object imaged by controlling the direction of imaging by the infrared camera to a desired one in a range of the imaging, a color image corresponding to a location, where the object has been imaged by the infrared camera, in a panoramic color image stored/managed in the server, and an image display for displaying an image produced by the overlaying by the image synthesizer.