The present invention provides a communication apparatus being in directly contact with a human body and using the human body as a transmission channel for data communication. The communication apparatus attached to the human body transmits a signal in the form of a current, receives a signal transmitted from another communication apparatus attached to the human body therethrough, and eliminates noise included in the received signal. In addition, the communication apparatus compares the noise-eliminated signal and a reference signal and recovers an original signal. Further, the communication apparatus generates a base-band signal and transmits the same through the human body.