A transceiver for inducing electric fields according to data to be transmitted in an electric field propagating medium, and carrying out data transmission by using induced electric fields and also carrying out data reception by receiving electric fields according to data to be received which are induced in the electric field propagating medium, the transceiver comprising: a transmission unit configured to generate alternating current signals having a prescribed frequency and to modulate the generated alternating current signals according to data to be transmitted; a transmission and reception electrode configured to induce the electric fields according to the data to be transmitted and receive the electric fields according to the data to be received; a resonance causing unit being provided at the output of the transmission unit and configured to vary the resonance frequency of a series circuit comprising a first parasitic capacitance occurring between a ground for the transmission unit and an earth ground, a second parasitic capacitance occurring between the electric field propagating medium and the earth ground, and the resonance causing unit by varying the reactance of the resonance causing unit, wherein the first parasitic capacitance, the second parasitic capacitance, and the resonance causing unit are connected in series from a view point of the transmission unit; an electric field detection unit (115, 117) configured to detect the electric fields induced in the electric field propagating medium and to convert each detected electric field into an electric signal; and a control unit (119, 121) configured to output a control signal for controlling the reactance of the resonant causing unit by using the electric signal converted by the electric field detection unit (115, 117). a transmission unit configured to generate alternating current signals having a prescribed frequency and to modulate the generated alternating current signals according to data to be transmitted; a transmission and reception electrode configured to induce the electric fields according to the data to be transmitted and receive the electric fields according to the data to be received; a resonance causing unit being provided at the output of the transmission unit and configured to vary the resonance frequency of a series circuit comprising a first parasitic capacitance occurring between a ground for the transmission unit and an earth ground, a second parasitic capacitance occurring between the electric field propagating medium and the earth ground, and the resonance causing unit by varying the reactance of the resonance causing unit, wherein the first parasitic capacitance, the second parasitic capacitance, and the resonance causing unit are connected in series from a view point of the transmission unit; an electric field detection unit (115, 117) configured to detect the electric fields induced in the electric field propagating medium and to convert each detected electric field into an electric signal; and a control unit (119, 121) configured to output a control signal for controlling the reactance of the resonant causing unit by using the electric signal converted by the electric field detection unit (115, 117).