Abstract: The disclosed mechanical arm comprises a base having mounted thereon a plurality of pivotally connected links, each having its own individual motor operatively connected through driving kinematic chains with said links, and a tensioning mechanism including a tensioning member and kinematic chains connecting said tensioning member with the links; said tensioning mechanism being provided with differential gears in a number equalling that of said driving kinematic chains tensioned by said tensioning member, one output of each said differential gears being connected to said individual motor, and two other outputs thereof being connected to the preceding and successive ones of said differential gears; the two unoccupied outputs of the terminal ones of said differential gears being connected, respectively, to said base and said tensioning member.The invention is primarily intended for automation of main and auxiliary operations in various industries, e.g. for handling of production tools and equipment.