A portable electric device such as a mobile phone is disclosed. The portable electric device comprises a first chassis and a second chassis, and the first chassis and the second chassis are foldably coupled. The first chassis comprises a case member that comprises a coupling recess, a first recess and a second recess. The coupling recess and the first recess face a same side of the case member. The second recess faces an opposite side of the case member to the coupling recess and the first recess. The second recess is located at a rear side of the coupling recess. The first recess and the second recess accommodate a first electronic component and a second electronic component, respectively.