A bill discrimination apparatus and method using a radio frequency (RF) signal that includes a transmission antenna radiating the radio frequency (RF) signal; a reception antenna receiving the RF signal from the transmission antenna; and a control unit providing the RF signal to the transmission antenna, and detecting a thickness of a bill, a state of the bill, or a presence of a foreign object on the bill based on a voltage of the RF signal transmitted through the bill and received by the reception antenna when the bill is between the transmission antenna and the reception antenna. The RF signal has a preset, specific frequency.