A touch sensor includes sensor electrodes formed on a transparent substrate by patterning an electroconductive polymer, and a see-through preventing layer in the vicinity of the outsides of the sensor electrodes on a surface different from the surface of the transparent substrate on which the sensor electrodes are disposed. The see-through preventing layer may be made of the same material as the sensor electrodes, and can not only reduce the visibility of the space between the sensor electrodes, but also reduce short-circuiting between the sensor electrodes.