A display device includes an image line and a position detecting line disposed in a display area and a signal processor, a first switch circuit, a second switch circuit, a common signal source, and a third switch circuit disposed outside the display area. The signal processor is configured to perform a feeding of an image signal and position detection with time-division. The first switch circuit is configured to electrically connect the image line to the signal processor in synchronization with the feeding of the image signal. The second switch circuit is configured to electrically connect the position detecting line to the signal processor in synchronization with the position detection. The common signal source is configured to feed a common signal. The third switch circuit is configured to electrically connect the position detecting line to the common signal source in synchronization with the feeding of the image signal.