A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an EFC antenna configured to transmit the RF signal as an electrostatic field or an induced electric field; and a receiver including an EFC antenna and a reception circuit unit configured to receive and process the RF signal received by the EFC antenna. The EFC antennas of the transmitter and the receiver each include a coupling electrode and a resonating section including a distributed-constant circuit configured to strengthen electrical coupling between the coupling electrodes. The RF signal is transmitted by electric-field coupling between the EFC antennas, facing each other, of the transmitter and the receiver.