The present technology relates to a communication device, a communication method, an integrated circuit, and an electronic instrument, which are capable of reducing a manufacturing cost of a communication device having both functions of an RF tag and reader/writer or an electronic instrument equipped with the communication device. A transmitting circuit transmits transmission data to a communication target by performing load modulation of changing an impedance of an antenna unit according to the transmission data using a first carrier generated in the antenna unit when the transmitting circuit operates in a first operation mode in which the transmitting circuit operates as an RFID reader/writer is performed, and the transmitting circuit transmits the transmission data to the RFID reader/writer by performing the load modulation of changing the impedance of the antenna unit according to the transmission data using a second carrier received by the antenna unit when the transmitting circuit operates in a second o
