A manipulator mechanism according to the present invention comprises an arm 1 having a tip mechanism 3 attached to its tip part, and an arm paying out device 2 to which the base end part of the arm 1 is coupled for winding and paying out the arm 1. The arm 1 comprises a tape aggregate 4 formed by bundling a plurality of elastic tapes 41, and a plurality of bundling members 5 attached to the tape aggregate 4 with spaces therebetween in a longitudinal direction of the tape aggregate 4. The bundling member 5 is provided with a guiding groove 51, through which the plurality of tapes 41 pass, to keep the relative position of the plurality of tapes 41 constant.