A mobile telephone having a main body and a sub-body closably mounted on the
main
body. The mobile telephone includes an opening/closing device installed in the
main body, for automatically opening and closing the sub-body against the main
body; a switch located at a specific place on the main body, for driving the opening/closing
device; a detector for detecting an opening angle of the opening/closing device;
and a controller for controlling rotation of the opening/closing device to a predetermined
opening angle by analyzing an output of the detector.
