1. A digital camera comprising: an image sensor which captures an object image via a photographing lens; a display device which displays an object image captured by said image sensor; an autofocus adjuster which detects a focal state based on said object image captured by said image sensor and brings a specified object image into an in-focus state, based on the detected focal state, by moving a focal-adjusting lens group of said photographing lens in the optical axis direction thereof; a focus lock-on device which prohibits said focal-adjusting lens group from moving in the optical axis direction, via the autofocus adjuster, and enters a focus locked-on state when the autofocus adjuster brings said specified object image into an in-focus state; a focus lock-on detector which detects whether or not said focus lock-on device is in a focus locked-on state; and a distinguishing-display controller which carries out image processing on at least a part of said specified object image, whereby a peaking display of the specified object image is displayed on said display device in a distinguished manner from the other object images, wherein said image processing and said peaking display of the specified object image are carried out by said distinguishing-display controller when said focus lock-on detector detects a focus locked-on state of said focus lock-on device.