ION PERMEABLE BODY

To provide an ion permeable body which does not crack and maintains a mechanical strength with durability even when processing a large amount of undiluted solution at a high speed.SOLUTION: An ion permeable body, which recovers metal ion from an aqueous solution containing the metal ion, comprises: an ion permeable membrane which is configured from an ion conductor particle and a fiber base material; and a mesh-like electrode which contacts one principal surface of the ion permeable membrane as a power collection body of electrons that generate when the metal ion permeates the ion permeable membrane. In the state that the ion permeable membrane enters inside a rectangular lattice space which is formed in such a manner that a vertical line and a transverse line of a metal wire constituting the electrode cross, a ratio of a surface area (S1) of the mesh electrode for power collection to a contact area (S2) between the ion permeable membrane and the mesh electrode for power collection is 0.2