An object of the present invention is to provide a receiver system that allows a plurality of antennas to be easily attached onto a body surface without losing receiving functions of the antennas while improving freedom for a living body. A receiver system transmits in-vivo information including in-vivo images received from a capsule endoscope (2) being the interior of a subject to an exterior receiving device (4) via a plurality of wireless relay devices (3). Each of the wireless relay devices (3a to 3h) includes a receiving unit (R1) that receives the in-vivo information from the capsule endoscope (2) at a first frequency (f1), a transmitting unit (S2) that transmits the in-vivo information at a second frequency (f2), a receiving unit (R2) that receives a control signal transmitted by the receiving device (4) at the second frequency (f2), and a control unit (C) that controls transmissions and receptions performed by the receiving unit (R1) and the transmitting unit (S2) based on the control signal.