A capsule medical system (1) is provided with a capsule medical device (2) to be inserted into the inside of a subject (K), at least one electrode pad (4a, 4b, 4c, 4d) having a plurality of receiving electrodes, a receiving electrode switching unit, a control unit for controlling operations of the receiving electrode switching unit, and a position detector (7). The capsule medical device has a biological information acquiring unit for acquiring biological information of the subject (K), and a transmitting unit for outputting the biological information from a transmitting electrode through a living body. At least one electrode pad (4a, 4b, 4c, 4d) detects the biological information by a plurality of receiving electrodes. The receiving electrode switching unit switches a pair of receiving electrodes among the plurality of receiving electrodes. The position detector detects a position of the capsule medical device inside the subject (K) based on the biological information detected by the electrode pad (4a, 4b, 4c, 4d), and position coordinate data of the plurality of receiving electrodes.