There are provided a portable terminal device capable of preventing influence on the surroundings and leakage of personal information without impairing convenience and its incoming call notifying operation controlling method. A portable terminal device (1) executes radio authentication between itself and a radio communicating unit (3). The portable terminal device (1) includes a radio communicating unit for conducting communication with a base station device; an incoming call notifying unit for executing an incoming call notification when an incoming call is detected by the radio communicating unit; an incoming call operation controlling unit for controlling the operation of the incoming call notifying unit; and a radio authenticating unit for conducting radio communication with the radio communicating unit (3) and authentication according to whether or not the distance to the radio communicating unit is within a predetermined distance. The incoming call operation controlling unit controls the operation of the incoming call notifying unit by an incoming call notifying method according to the distance to the radio communicating unit (3).