OPERATION INPUT DEVICE

An operation input device is provided with: a knob for operations, disposed in a display region of a touch display; a conductor column that is provided in the knob, and that can be detected as a touch point irrespective of whether or not the knob is in a state of being touched with user's finger; a touch point detecting unit for detecting a plurality of touch points including the touch point corresponding to the conductor column, and outputting touch information related to the plurality of detected touch points; a knob touch point determining unit for determining, by using the touch information, the touch point corresponding to the conductor column among the plurality of touch points detected by the touch point detecting unit; and a touch strength value calculating unit for calculating a touch strength value at the touch point corresponding to the conductor column by using the touch information and a determination result by the knob touch point determining unit; and a finger-touch-on-the-knob determining unit for determining, by using the touch strength value, whether or not the knob is in a state of being touched with user's finger.