A mobile phone of the present invention has a structure in which a second case is provided with a sub-display unit and an LED for indicating an incoming call, both of which can be watched even in a state where the mobile phone is folded. The sub-display unit is provided on a back surface opposite to a main surface on which a main display unit is provided. Moreover, the mobile phone of the present invention is provided with a sub-operation unit on a side surface of a first case. The sub-operation unit is provided with a first operation key, a second operation key, and a third operation key. Correspondingly to these keys, a short cut function is registered in a storage unit for setting a useful function (for example, a ring tone, an LED for indicating an incoming call, or the like) for a case in which a change is made in a state where the mobile phone is folded.