With a simple configuration, a area in which an operating unit can move is prevented from being limited. Provided is an operation input device (1) including a display (5) an operating unit (7) that operates a display object (2) displayed on the display (5) a head-mounted unit (6) that is mounted on the head (C) of an operator (B) relative position sensors (9 and 12) that detect a relative position and a relative orientation of one of the head-mounted unit (6) and the operating unit (7) with respect to the other and a control unit (8) that actuates the display object (2) displayed on the display (5) on the basis of changes in the relative position and the relative orientation detected by the relative position sensors (9 and 12).
