A communication device includes a proximity wireless communication antenna for contactless proximity wireless communication with a counterpart instrument antenna in proximity, a first wireless communication processing unit to conduct contactless proximity wireless communication using the proximity wireless communication antenna, a second wireless communication processing unit to conduct wireless communication in a wireless communication format different from that of the first processing unit, a ground potential to be disposed in a surrounding area of the proximity wireless communication antenna and to be connected to a counterpart instrument ground potential when the instrument is in proximity, a detection unit to detect that the counterpart instrument is connected while allowing contactless proximity wireless communication, and a control unit to restrict wireless communication with the second processing unit when the detection unit detects connection and to remove the restriction after connected to the counterpart instrument ground potential with the ground potential during the restriction.