A receiving device includes a receiving unit that receives, via a receiving antenna, an image signal including an in-vivo image of a subject that is captured by an in-vivo-image acquiring device introduced into the subject a transmitting unit that wirelessly transmits the image signal to a real-time display device that displays the in-vivo image in real time a detecting unit that detects a non-receiving period in which the receiving unit does not receive the image signal and a control unit that performs a control to wirelessly transmit the image signal to the real-time display device during the non-receiving period immediately after receipt of the image signal by the receiving unit.
