A portable telephone set includes a telephone set main body and a flipper. The telephone set main body is provided with a hinge mechanism and a flipper joint plate. The flipper joint plate is pivotally supported by hinge modules and has a connector at an end thereof. The flipper is joined to the flipper joint plate. The flipper is provided with a cable accommodating portion in which a short cable with a connector is accommodated. The cable includes a short cable main body as long as, for example, 10 cm and two connectors at respective ends of the cable. For mobile communication, one of the connectors of the cable is taken out from the flipper and connected to an information processing device.