An operation input device includes an operation body, a case holding the operation body, and at least three flexible bodies. The operation body includes an operation body movable part and a movable part driver. The operation body movable part has a touch surface having a predetermined touch surface region. The movable part driver causes the operation body movable part to move a touch surface position where the touch surface region is flush with a remaining region of the touch surface and a button position located above or below the touch surface position. Each flexible body is connected at one end to an outer edge of the operation body, connected at the other end to the case, and has a displacement-transmitting surface capable of being displaced according to a pressing operation force applied to the operation body by a pressing operation to the touch surface.