An insertion device (1) is provided with: an elongated insertion unit (110); a rotatable cylinder body (132) provided on the outer peripheral surface of the insertion unit (110) so as to be capable of rotating about a longitudinal axis; a motor (150) for rotating the rotatable cylinder body (132); a fin (134) formed spirally on the outer peripheral surface of the rotatable body (132) and moving the insertion section (110) in the insertion direction or the extraction direction as a power spiral tube (132) rotates; and a control unit (202) for specifying the rotational direction and rotational speed of the motor (150). When starting inspection control, the control unit (202) limits the rotational direction of the motor (150) so as to only permit the insertion section (110) to move in the extraction direction.
