An in-vivo information acquisition system of the invention is an in-vivo information acquisition system including an in-vivo information acquisition apparatus provided with a configuration capable of transmitting a wireless signal which includes in-vivo information about an inside of a subject, and a terminal apparatus provided with a configuration capable of receiving the wireless signal transmitted from the in-vivo information acquisition apparatus outside the subject, wherein the terminal apparatus includes a reception confirmation signal transmission section generating and transmitting a reception confirmation signal when the wireless signal which includes the in-vivo information about the subject can be received and the in-vivo information acquisition apparatus includes a storage section, and a control section causing the wireless signal which includes the in-vivo information about the subject to be transmitted and at the same time, causing the same in-vivo information as included in the transmitted wireless signal to be stored into the storage section at least during a period during which the reception confirmation signal cannot be received.
