An operation estimating portion estimates an input operation on the basis of motions of a nail and a finger which are shot, the directions, the number thereof or others. On the basis of estimation results of the input operation, a controller controls display content on a display and an application now in execution. The operation estimating portion includes a skin region extractor for extracting a skin region (first region) containing a nail region (second region) from a shot image, a nail region extractor for extracting the nail region from the thus extracted skin region, and a motion detector for following up a temporal change in the thus extracted nail region to detect motions of the nail region, thereby estimating the input operation on the basis of detection results of the motion detector.