Provided is a manipulator including: a movable part a drive unit generating power an elongated flexible long guide member to which the part is attached at one end thereof and the drive unit is attached at the other end thereof an elongated tension transmission member passing through a lumen in the long guide member and transmitting the power of the drive unit to the part by means of a tension a tension adjusting mechanism adjusting the tension of the tension transmission member and a holding unit to which the drive unit is detachably attached. The mechanism includes: a tensioner, provided in a movable manner in a direction intersecting the longitudinal direction of the tension transmission member, that pulls the tension transmission member and a pressing member, provided in the holding unit, that moves the tensioner in a state in which the drive unit has been attached to the holding unit.
