The invention relates to a manipulator comprising an end effector (27) displaceable by means of a rod mechanism comprising four arms (11,13,15,17). By means of simultaneously activated individual drives (29,35) for two of the arms (11,15) which are of equal length, which individual drives are integrated in a differential drive, a displacement of the rod mechanism is obtained in a plane at right angles to a main axis (3) about which the two arms (11,15) are rotatable. At the same and oppositely directed angular velocities of the arms (11,15) about the main axis (3), a radial (R) positioning of the end effector (27) takes place, while at the same angular velocities of the arms (11,15) in the same direction an angular (.theta.) displacement of the end effector (27) about the main axis is obtained. The manipulator is particularly suitable for use as assembling robot.