A touch sensor device is provided. The touch sensor device includes a touch panel including a plurality of touch mark-keys indicating a position touched by a touch object, a plurality of first touch pads disposed at positions corresponding to the plurality of touch mark-keys of the touch panel and generating touch information of the touch object as a first electrical signal, a plurality of second touch pads disposed between the plurality of first touch pads and generating touch information of a conductive material on the touch object as a second electrical signal, and a touch sensing unit receiving the first electrical signal, outputting a plurality of sensing signals to allow an electronic device to perform predetermined operations corresponding to the touched touch mark-keys, and determining whether the touch of the touch object is a normal one using the first and second electrical signals.