An operation device for an into-bore introduction device, includes: a grasping section connected to a proximal portion of an insertion section to be inserted into a bore, and is to be grasped by an operator to operate the insertion section; a bending operation knob disposed on the grasping section and bends a bending portion of the insertion section; a projecting portion formed to project from the grasping section in a direction radial to a longitudinal axis of the grasping section, in a surface between a surface on which the bending operation knob is disposed and a surface on which operator's palm abuts to grasp the grasping section, in the grasping section; and an inclined surface inclined toward the insertion section on an insertion section side of the projecting portion.