To perform further pliable assembly work by a method wherein a force generated at a compliance mechanism is detected and based on a detecting force, feedback control is performed.

The arm mechanism having three sets of links 13 is formed such that the arm mechanism of an assembly robot comprises a cylinder member 15 and a rod member 16, and forms a direct acting mechanism having one degree of freedom, the end part of the cylinder member 15 is coupled in such a manner to be rotated integrally with the rotary shaft 14a of the rotation motor 14, and the end pat of the rod member 16 is rotatably coupled to a moving body 12. A torque sensor 22 to detect torque of a rotary motor 14 is provided. Based on the detecting torque, feedback control is effected.