The invention relates to a mobile terminal and hinge device thereof. The mobile terminal comprises: a first keypad disposed with a plurality of keys in the upper face of the main body at one side from a central portion so that the keys can be exposed; a second keypad disposed with a plurality of keys in the upper face of the main body at the other side from the central portion so that the keys can be exposed; and a planar area disposed in the central portion of the upper face of the main body to which the sub-body is rotatably connected, whereby one of the first and second keypads is opened and closed according to rotation of the sub-body. The mobile terminal introduces a novel concept including design by coupling the sub-body to the main body in a manner horizontally rotatable with respect to the upper face of the main body to open/close the keypad at least at one side of the main body. Furthermore, the keypads at both sides can be used together when the sub-body is rotated perpendicular to the main body, allowing more rapid input of information via both keypads and without any additional input device.