A mobile communication device is provided that includes a first body, a second body hingedly-coupled to the first body and speaker unit installed in the second body such that sound generated when the first body is folded closed with respect to the second body can be directly transferred outside the mobile communication device. Using the present invention, a user can listen to high-quality reproduced sound without distortion even when the first body is folded closed with respect to the second body and reliability and competitiveness of a product can be improved.