There is provided a portable terminal device that enables a user to operate all buttons to be operated by moving only one finger of one hand carrying the terminal when operating the terminal equipped with both a touch panel and a stationary operation section and that exhibits superior operability. The portable terminal device has enclosures 11, 12 with a movable portion, a display section 17 capable of displaying visible information showing an operation target area, and a touch sensor 13 that detects a position on a display screen of the display section touched by a user's finger, or the like. The device is further provided with a shape detection section for detecting a change in the shape of the enclosure; an input operation management section for managing a position detected by the touch sensor and an operation target area of each of pieces of visible information displayed on the display section in an associated manner; and a display control section that automatically makes a change to at least display positions of the respective pieces of visible information about the operation target displayed on the display section in accordance with a change in shape of the enclosure detected by the shape detection section.