A first substrate that includes pressure sensors which are disposed in plural around a reference point; an approximately hemispherical elastic protrusion that is positioned so that the center of the elastic protrusion is approximately disposed in a position which is overlapped with the reference point, and is elastically deformed by an external force; and a second substrate that is separated from the elastic protrusion and installed on a side which is opposite to the first substrate are provided. When the external force is applied, a predetermined calculation is performed by using a pressure value which is detected through each pressure sensor, and the direction and the intensity of the applied external force are obtained.