A device includes a photographing unit, an image processing unit, a buffer, a storage unit, and a digital signal processor. The buffer stores index information to be assigned to at least one image signal obtained by the photographing unit, file name and storage path information to be provided to the at least one image signal when the at least one image signal is stored in the storage unit. The digital signal processor displays the most recently stored image signal when a display input instruction to display a currently captured image is received, searches the storage unit when an input instruction to display previously-captured images is additionally received, if a corresponding image file is found in the storage unit, displays the found image file, and if the corresponding image file is not found in the storage unit, displays an image signal stored in the buffer using the index information.