Provided is an image sensing apparatus in which it is possible to use an optical system having a large aperture and an image sensing system such as an image sensing element in an image sensing cartridge docked with a portable image device. The image sensing apparatus includes a portable information device and an image sensing cartridge, which has at least an image sensing system, capable of being loaded in and unloaded from the information device. An image sensing operation becomes possible by docking the information device and the image sensing cartridge. The image sensing cartridge has an opening, which is for introducing light to the image sensing system, the aperture of which is designed to be larger than the shortest portion of an insertion port, which is provided in the information device, for inserting the image sensing cartridge.