A manipulator comprises a hollow shaft, wires provided on the shaft and a working unit disposed on one end of the shaft and being driven by at least one wire of the wires, the working unit having a tip tool including a rolling mechanism which rotates about an axis Or directed to a distal end thereof. A tip side surface of a proximal end member and a cover of a distal end member are relatively rotated by the rolling mechanism. The cover has a rotation identifier for indicating a degree of relative rotation of the tip side surface. The tip side surface has an alignment indicator for indicating an initial position of the cover.