An ion-dielectric touch sensor detects a touching operation applied by a touching object thereto. The ion-dielectric touch sensor includes a base board, a first electrode, a second electrode, and a dielectric layer. The base board forms an electrode mounting surface on which the first and second electrodes are arranged in such a way that the second electrode is closed to but spaced from the first electrode. The dielectric layer is coated on the electrode mounting surface of the base board and encloses the first and second electrodes. When the touching object touches the dielectric layer of the ion-dielectric touch sensor, a variation of the electrical resistance between the first and second electrodes is caused. The variation of electrical resistance is detected by a detection circuit connected between the first and second electrodes.