A UWB repeater preferably applied to a relay of stream data, which does not require frequency conversion and has less delay in relay. The UWB repeater includes a receiving antenna, a receiver, a transmitter, a transmitting antenna, and a relay controller. The relay controller is provided with a switch unit, a delay, and a transmitting/receiving timing controller. UWB pulse signals demodulated by the receiver are power-amplified by the transmitter and transmitted after being delayed by the delay unit for timing that does not overlap the receiving timing. The transmitting/receiving timing controller turns on the switch unit during the period of pulse receiving timing and enables a relay of the receiving pulses, and turns off the switch unit during the period of relaying of pulses, and can prevent sneak path signals between the transmitting side and the receiving side.