1. An imaging apparatus comprising: imaging means for photographing an area, while sequentially setting a photographing direction to unit images that constitute a panorama image of the entire area; panorama-image generating means for generating a panorama image by combining a plurality of unit images obtained by the imaging means, the panorama-image generating means generating the panorama image by spatially combining the plurality of unit images such that the panorama image is larger than any of the unit images; panorama-image storage/management means for storing and managing the panorama image generated by the panorama-image generating means; infrared imaging means for photographing an object that emanates infrared rays as an infrared image; direction control means for sequentially shifting the photographing direction of the infrared imaging means within the area being photographed; infrared-image generating means for combining a plurality of infrared images provided by the infrared imaging means, thereby to generate a panorama infrared image of the entire area, the infrared-image generating means generating the panorama infrared image by spatially combining the plurality of infrared images such that the panorama infrared image is larger than any of the infrared images; image-synthesizing means for synthesizing the panorama image generated by the panorama-image generating means, with the panorama infrared image generated by the infrared-image generating means to create a synthesized image; and image-displaying means for displaying the synthesized image generated by the image-synthesizing means.