A working robot, which is able to perform a required operation by locating a tool on a working position of a moving object, comprises a robot body moving with the object according to the movement of the object with more than one degree of freedom; an actuator mounted on a free end of the robot body and including a tool mounting unit, on which the tool is mounted, connected by a passive joint which reacts passively to small displacement of the object for locating the tool on the working position; and a control device for controlling the robot body, the actuator, and the tool.