A portable digital communication device, in which it is convenient to manipulate keys using fingers of both hands while chatting or playing a game. The device comprises a main housing provided with a display unit on a top surface thereof, a first key pad being capable of sliding on the top surface of the main housing in one direction relative to the display unit so as to open and close one side of the display unit, and a second key pad being capable of sliding on the top surface of the main housing in the other direction relative to the display unit so as to open and close the other side of the display unit and being capable of sliding toward or away from the first key pad.