There is disclosed a mobile terminal including a front case, a first rear case shaped to cover a first area of a rear surface of the front case, a second rear case shaped to cover the second area of the rear surface of the front case, a tightening groove formed in the portion where the first rear case and the second rear case are coupled with each other and comprising inclined surfaces a first tightening rib projected from a front surface of the first rear case and comprising an inclined surface corresponding to one inclined surface of the tightening groove, a second tightening rib projected from the front surface of the second rear case and comprising an inclined surface corresponding to the other inclined surface of the tightening groove, wherein the first tightening rib and the second tightening rib are inserted in the tightening groove.