To improve tightness for sealed liquid without increasing the size of a tablet input device which is provided with liquid sealed between an upper movable electrode and a lower fixed electrode opposed to each other in order to improve visibility.

A transparent reinforcing film 7 is stuck to the outer surface of an upper movable electrode 1 consisting of a transparent film, a transparent reinforcing film 8 is stuck to the outer surface of a lower fixed electrode 2 consisting of transparent glass, both the electrodes 1, 2 are opposed to each other at a prescribed interval and fixed and held by a distance piece 4 applied to all peripheral parts, and liquid 5 is sealed in an inner space. A sealing material 6 having a sufficient thickness is applied to the whole peripheral end surfaces of the film 7, the electrode 1, the piece 4, the electrode 2, and the film 8 and cured, so that the whole parts are integrally formed and the filled solution 5 is sealed tight.