Abstract: The hand-operated ratchet spanner contains a measuring value pick-up (4,9) for the angle of rotation of the screw and a device for measuring the torque. The measured values are supplied to a microprocessor (22) in which the screw tightening operation is preprogrammed by respective desired or limit values. Signal lamps (30,31,32) or acoustic signal transmitters (33) indicate to the user as to whether the screw has been correctly tightened. Further, he may recognize the extent to which the screw has been tightened and which part of the tightening operation must be still effected.