An operation device for an into-bore introduction device, includes: a projecting portion formed to project from a grasping section in a radial direction to a longitudinal axis of the grasping section, in a surface between a surface on which a bending operation knob is disposed and a surface on which operator's palm abuts to grasp the grasping section, in the grasping section； a pressing switch disposed on the projecting portion； and an inclined surface formed distantly by as much as a predetermined distance from the pressing switch, and in which an amount of the inclined surface to project outside in the radial direction is decreased on an insertion section side of the projecting portion.
