A portable-terminal holder for holding a portable terminal that has a rechargeable battery and a first radio communication device is constituted by a base and c communication module. The base has a portion on which the portable terminal is placed, and a charging device for charging the rechargeable battery of the portable terminal while said portable terminal is placed on the portion. The communication module has a second radio communication device communicating with the first radio communication device for wireless data transmission between the portable terminal and the communication module, and a cable communication device communicating with an external host computer for cable data transmission between the host computer and the communication module. The communication module is configured to be detachable from the base.