Electronic apparatus for electric field communication

An electronic device for electric field communication is provided which can perform communications even if a case-wall of an electronic device facing a transmission medium is not the case-wall on which a signal electrode is provided and which achieves a usability that allows the user to communicate without paying attention to which case-wall of the electronic device is a front or back one thereof. A circuit board (12) is provided inside a case (11). A signal electrode (13), which transmits and/or receives electric field signals, is provided on a first case-wall of the case (11). The signal electrode (13) is electrically connected to a conductive part (16) of the circuit board (12) that is a device component. A battery (14) and a reference electrode (15) having a reference potential of an electric field, both of which are also device components, are provided on a second case-wall of the case (11). The sum of capacitances (Cst) occurring between the transmission medium (2) and the respective ones of the signal electrode (13) and device components when the first case-wall faces the transmission medium (2) is approximately equal to the sum of capacitances (Cgt) occurring between the transmission medium (2) and the respective ones of the device components when the second case-wall faces the transmission medium (2).