An embodiment of the invention provides a liquid crystal display device, including a first substrate; a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; a first sensor electrode formed on the first substrate; a second sensor electrode formed on the second substrate, and disposed so as to be adapted to contact the plurality of first sensor electrodes close to one another by pressing from a side of either the first substrate or the second substrate; and a sensor drive circuit for applying a voltage to a first wiring electrically connected to one of the plurality of first sensor electrodes which the second sensor electrode is adapted to contact by the pressing, and detecting a change in potential of a second wiring electrically connected to another one of the plurality of first sensor electrodes.