Abstract: The present invention relates to a mobile cellular phone, the mobile cellular phone including: a radio handset and a mobile cellular phone body for transmitting and receiving a sound and a signal information through a wireless channel; and a holder disposed in the body for accommodating the radio handset so that when the radio handset is detached from the holder the body can relay the sound and the signal information between the radio handset and a base station to thereby enable a telecommunication to be realized through the radio handset and when the radio handset is accommodated in the holder, the telecommunication can be realized through the body.