Umbilical member arrangement unit of robot arm section

An umbilical member arrangement unit of a robot arm section for avoiding interference between the umbilical member and external equipment has a first fixing member attached to a nonrotating part and adapted to nonslidably fix the umbilical member, and a second fixing member attached to a rotating part so as to integrally rotate with the rotating part and adapted to nonslidably fix the umbilical member. When the rotating part is positioned at a center position of a rotational motion range thereof about the longitudinal axis, the first and second fixing members direct the umbilical member along first and second tangential lines, respectively, the two tangential lines being generally perpendicular to each other, and, the fixing members are positioned in the same region in relation to two regions defined by a boundary plane parallel to the second tangential line, on which the longitudinal axis lies.