PURPOSE: To provide a medical capsule which decreases the pain of a patient, and can be detained and used continuously in a living body for many hours.

CONSTITUTION: In the medical capsule 1 detained in the living body, the capsule is provided with a capsule main body 4, an electric circuit provided on this capsule main body 4, a battery 9 connected to the electric circuit and provided in the capsule main body 4 and an energy replenishing part 2 which is provided in the capsule main body 4 and replenishes energy to the battery 9. Also, the capsule is provided with a connecting means for connecting the energy replenishing part 2 and an energy supply means 24 provided on the outside of the capsule main body 4 so as to be freely attachable/detachable and a cutting-off means for cutting off the energy replenishing part from the open air when the energy replenishing part and the energy supply means are not connected.