Abstract: A foot prosthesis has an inner spring that extends from the heel area to the front area of the foot. The foot spring is enclosed within a cosmetic lining and is joined by a threaded bolt to an adapter with a clamping connection for removably joining the foot prosthesis to a prosthesis tube. The adapter is supported by its lower face, which is designed as a cylinder segment and is provided with serrations, on a joining surface of the inner spring. The joining surface of the inner spring has a shape corresponding to the lower face of the adapter, and has serrations for engaging the adapter's serrations. The upper end of the adapter is designed as a peg which is inserted into the prosthesis tube. The threaded bolt is inserted through a slot that extends in the longitudinal direction of the foot and has a width corresponding to the diameter of the bolt.