A portable telephone having a portable telephone function and a game machine function such as for a music game using a vibration device such as a vibration sensor or a vibration motor. When the user shakes the portable telephone like a maraca in rhythm with a predetermined tune, a vibration device generates a vibration pulse, which is compared with a rhythm pulse. Then the shaking of the portable telephone by the user is rated according to the difference in time between the vibration pulse and a rhythm pulse, and the score is displayed on the screen of a display.