A mobile terminal device includes: a housing; a touch panel-equipped display section; a sensor; and a control unit including a processor and, upon execution of a control program by the processor, functioning as a display control section, an operating region decision section, an operating region storage section, a specific inclination determination section, and a display change section. The operating region decision section determines, during holding of the housing with a user's one hand, an operating region on the screen of the display section reachable with an operating finger of the one hand from a trace of points of touch with the operating finger. When an inclination of the housing detected by the sensor is determined to be a specific inclination toward the operating finger by the specific inclination determination section, the display change section moves and displays a plurality of on-screen objects into and within the operating region.